Virgin import of FSF groff v1.17

5 files changed, 3908 insertions, 2567 deletions

diff --git a/contrib/groff/doc/Makefile b/contrib/groff/doc/Makefile
index 042bbe0..408e6e1 100644
--- a/contrib/groff/doc/Makefile
+++ b/contrib/groff/doc/Makefile
@@ -26,7 +26,7 @@ MEMACROS=../tmac/tmac.e
 SOELIM=../src/preproc/soelim/soelim
 
 version=`cat ../VERSION`
-# No additional number for the groff archive if revision is zero
+# No additional number if revision is zero
 revision=`sed -e 's/^0$$//' -e 's/^[1-9].*$$/.&/' ../REVISION`
 
 all: $(DOCS)
@@ -54,13 +54,13 @@ all: $(DOCS)
 	GROFF_TMAC_PATH=../tmac; \
 	export GROFF_TMAC_PATH; \
 	sed -e "s;@VERSION@;$(version)$(revision);" $< \
-	| $(GROFF) -Tascii $(FFLAG) -U -ms -markup >$@
+	| $(GROFF) -Tascii $(FFLAG) -U -ms -mwww >$@
 
 .ms.ps:
 	GROFF_TMAC_PATH=../tmac; \
 	export GROFF_TMAC_PATH; \
 	sed -e "s;@VERSION@;$(version)$(revision);" $< \
-	| $(GROFF) -Tps $(FFLAG) -U -ms -markup >$@
+	| $(GROFF) -Tps $(FFLAG) -U -ms -mwww >$@
 
 .texinfo.dvi:
 	texi2dvi -e $<
diff --git a/contrib/groff/doc/groff.texinfo b/contrib/groff/doc/groff.texinfo
index ca13abb..b537d1a 100644
--- a/contrib/groff/doc/groff.texinfo
+++ b/contrib/groff/doc/groff.texinfo
@@ -1,9 +1,8 @@
 \input texinfo   @c -*-texinfo-*-
 
 @c
-@c If you use texinfo.tex 1999-09-25.10 or earlier please convert this
-@c manual with `texi2dvi -e groff.texinfo' due to a bug in expanding
-@c user-defined macros.
+@c Please convert this manual with `texi2dvi -e groff.texinfo' due to a bug
+@c in texinfo regarding expansion of user-defined macros.
 @c
 
 @c %**start of header (This is for running Texinfo on a region.)
@@ -17,55 +16,182 @@
 @c We use the following indices:
 @c
 @c   cindex: concepts
-@c   findex: requests, escapes, and functions
+@c   rqindex: requests
+@c   esindex: escapes
 @c   vindex: registers
 @c   kindex: commands in font files
 @c   pindex: programs and files
 @c   tindex: environment variables
-@c   maindex: macros and strings
+@c   maindex: macros
+@c   stindex: strings
 @c   glindex: glyph names
 @c   opindex: operators
 @c
 @c tindex and cindex are merged.
 
+@defcodeindex rq
+@defcodeindex es
 @defcodeindex ma
+@defcodeindex st
 @defcodeindex gl
 @defcodeindex op
 @syncodeindex tp cp
 
 
-@macro Deffn{category, name, arg}
-@deffn \category\ @t{\name\} \arg\
+@c to avoid uppercasing in @deffn while converting to info, we define
+@c our special @Var{}
+@c
+@c due to a (not officially documented) `feature' in makeinfo 4.0,
+@c macros are not expanded in @deffn (but the macro definition is
+@c properly removed), so we have to define @Var{} directly in TeX also
+
+@macro Var{arg}
+\arg\
+@end macro
+@tex
+\gdef\Var#1{\var{#1}}
+@end tex
+
+
+@c definition of requests
+
+@macro Defreq{name, arg}
+@rqindex \name\
+@deffn Request @t{.\name\} \arg\
+@end macro
+
+@macro Defreqx{name, arg}
+@rqindex \name\
+@deffnx Request @t{.\name\} \arg\
+@end macro
+
+@macro endDefreq
+@end deffn
+@end macro
+
+
+@c definition of escapes
+
+@macro Defesc{name, delimI, arg, delimII}
+@esindex \name\
+@deffn Escape @t{\name\\delimI\}@var{\arg\}@t{\delimII\}
 @end macro
 
-@macro end_Deffn
+@macro Defescx{name, delimI, arg, delimII}
+@esindex \name\
+@deffnx Escape @t{\name\\delimI\}@var{\arg\}@t{\delimII\}
+@end macro
+
+@macro endDefesc
 @end deffn
 @end macro
 
-@macro Deffnx{category, name, arg}
-@deffnx \category\ @t{\name\} \arg\
+
+@c definition of registers
+
+@macro Defreg{name}
+@vindex \name\
+@deffn Register @t{\\n[\name\]}
+@end macro
+
+@macro Defregx{name}
+@vindex \name\
+@deffnx Register @t{\\n[\name\]}
 @end macro
 
-@macro end_Deffnx
-@end deffnx
+@macro endDefreg
+@end deffn
 @end macro
 
+
+@c definition of macros
+
 @macro Defmac{name, arg}
-@defmac @t{\name\} \arg\
+@maindex \name\
+@defmac @t{.\name\} \arg\
+@end macro
+
+@macro Defmacx{name, arg}
+@maindex \name\
+@defmacx @t{.\name\} \arg\
 @end macro
 
-@macro end_Defmac
+@macro endDefmac
 @end defmac
 @end macro
 
-@macro Defmacx{name, arg}
-@defmacx @t{\name\} \arg\
+
+@c definition of strings
+
+@macro Defstr{name, arg}
+@stindex \name\
+@deffn String @t{\name\} \arg\
 @end macro
 
-@macro end_Defmacx
-@end defmacx
+@macro Defstrx{name, arg}
+@stindex \name\
+@deffnx String @t{\name\} \arg\
 @end macro
 
+@macro endDefstr
+@end deffn
+@end macro
+
+
+@c our example macro
+
+@macro Example
+@example
+@group
+@end macro
+
+@macro endExample
+@end group
+@end example
+@end macro
+
+
+@c We need special parentheses and brackets:
+@c
+@c . Real parentheses in @deffn produce an error while compiling with
+@c   TeX
+@c . Real brackets use the wrong font in @deffn, overriding @t{}.
+@c
+@c This is true for texinfo 4.0.
+
+@ifnottex
+@macro lparen
+(
+@end macro
+@macro rparen
+)
+@end macro
+@macro lbrack
+[
+@end macro
+@macro rbrack
+]
+@end macro
+@end ifnottex
+
+@iftex
+@macro lparen
+@@lparen
+@end macro
+@macro rparen
+@@rparen
+@end macro
+@macro lbrack
+@@lbrack
+@end macro
+@macro rbrack
+@@rbrack
+@end macro
+@end iftex
+
+
+@c Note: We say `Roman numerals' but `roman font'.
+
 
 @c XXX comment all examples
 
@@ -186,24 +312,26 @@ contributions are welcome.  Send them to bug-groff@@gnu.org.
 @end ifinfo
 
 @menu
-* Copying::                     
-* Introduction::                
-* Invoking groff::              
-* Tutorial for Macro Users::    
-* Macro Packages::              
-* Programming Tutorial::        
-* Preprocessors::               
-* Output Devices::              
-* File formats::                
-* Installation::                
-* Request and Escape Index::    
-* Operator Index::              
-* Register Index::              
-* Macro and String Index::      
-* Glyph Name Index::            
-* Font File Keyword Index::     
-* Program and File Index::      
-* Concept Index::               
+* Copying::
+* Introduction::
+* Invoking groff::
+* Tutorial for Macro Users::
+* Macro Packages::
+* gtroff Reference::
+* Preprocessors::
+* Output Devices::
+* File formats::
+* Installation::
+* Request Index::
+* Escape Index::
+* Operator Index::
+* Register Index::
+* Macro Index::
+* String Index::
+* Glyph Name Index::
+* Font File Keyword Index::
+* Program and File Index::
+* Concept Index::
 @end menu
 
 
@@ -617,13 +745,13 @@ use) for about 3@w{ }decades.  It is quite widespread and firmly
 entrenched in the @acronym{UNIX} community.
 
 @menu
-* What Is groff?::              
-* History::                     
-* groff Capabilities::          
-* Macro Package Intro::         
-* Preprocessor Intro::          
-* Output device intro::         
-* Credits::                     
+* What Is groff?::
+* History::
+* groff Capabilities::
+* Macro Package Intro::
+* Preprocessor Intro::
+* Output device intro::
+* Credits::
 @end menu
 
 
@@ -644,17 +772,16 @@ then be processed by @code{groff} to produce a typeset document on a
 variety of devices.
 
 Likewise, @code{groff} should not be confused with a @dfn{word
-processor}, since that term connotes an integrated system which includes
+processor}, since that term connotes an integrated system that includes
 an editor and a text formatter.  Also, many word processors follow the
-@acronym{WYSIWYG} paradigm which was discussed earlier.
+@acronym{WYSIWYG} paradigm discussed earlier.
 
 Although @acronym{WYSIWYG} systems may be easier to use, they have a
 number of disadvantages compared to @code{troff}:
 
 @itemize @bullet
 @item
-They must be used on a graphics display to do any operations on a
-document.
+They must be used on a graphics display to work on a document.
 
 @item
 Most of the @acronym{WYSIWYG} systems are either non-free or are not
@@ -691,26 +818,26 @@ impossible to accomplish complex actions.''  --Doug Gwyn (22/Jun/91 in
 operating system in the mid-sixties.  This name came from the common
 phrase of the time ``I'll run off a document.''  Bob Morris ported it to
 the 635 architecture and called the program @code{roff} (an abbreviation
-of @code{runoff}).  It has then been rewritten as @code{rf} for the
-PDP-7 (before having @acronym{UNIX}), and at the same time (1969), Doug
+of @code{runoff}).  It was rewritten as @code{rf} for the @w{PDP-7}
+(before having @acronym{UNIX}), and at the same time (1969), Doug
 McIllroy rewrote an extended and simplified version of @code{roff} in
 the @acronym{BCPL} programming language.
 
 @cindex @code{roff}
-The first version of @acronym{UNIX} was developed on a PDP-7 which was
-sitting around Bell Labs.  In 1971 the developers wanted to get a PDP-11
-for further work on the operating system.  In order to justify the cost
-for this system, they proposed that they would implement a document
-formatting system for the AT&T patents division.  This first formatting
-program was a reimplementation of McIllroy's @code{roff}, written by
-J.@w{ }F.@w{ }Ossanna.
+The first version of @acronym{UNIX} was developed on a @w{PDP-7} which
+was sitting around Bell Labs.  In 1971 the developers wanted to get a
+@w{PDP-11} for further work on the operating system.  In order to
+justify the cost for this system, they proposed that they would
+implement a document formatting system for the AT&T patents division.
+This first formatting program was a reimplementation of McIllroy's
+@code{roff}, written by J.@w{ }F.@w{ }Ossanna.
 
 @cindex @code{nroff}
 When they needed a more flexible language, a new version of @code{roff}
 called @code{nroff} (``Newer @code{roff}'') was written.  It had a much
 more complicated syntax, but provided the basis for all future versions.
 When they got a Graphic Systems CAT Phototypesetter, Ossanna wrote a
-version of @code{nroff} which would drive it.  It was dubbed
+version of @code{nroff} that would drive it.  It was dubbed
 @code{troff}, for ``typesetter @code{roff}'', although many people have
 speculated that it actually means ``Times @code{roff}'' because of the
 use of the Times font family in @code{troff} by default.  As such, the
@@ -733,7 +860,7 @@ preprocessor for formatting tables.  The @code{refer} preprocessor (and
 the similar program, @code{bib}) processes citations in a document
 according to a bibliographic database.
 
-Unfortunately, Ossanna's @code{troff} was written in PDP-11 assembly
+Unfortunately, Ossanna's @code{troff} was written in @w{PDP-11} assembly
 language and produced output specifically for the CAT phototypesetter.
 He rewrote it in C, although it was now 7000@w{ }lines of uncommented
 code and still dependent on the CAT.  As the CAT became less common, and
@@ -769,8 +896,8 @@ A replacement for @code{ditroff} with many extensions.
 The @code{soelim}, @code{pic}, @code{tbl}, and @code{eqn} preprocessors.
 
 @item
-Postprocessors for character devices, @acronym{PostScript}, @TeX{} DVI,
-and X@w{ }windows.  GNU @code{troff} also eliminated the need for a
+Postprocessors for character devices, @sc{PostScript}, @TeX{} DVI, and
+X@w{ }windows.  GNU @code{troff} also eliminated the need for a
 separate @code{nroff} program with a postprocessor which would produce
 @acronym{ASCII} output.
 
@@ -792,8 +919,8 @@ version@w{ }1.04 around November@w{ }1991.
 
 Beginning in@w{ }1999, @code{groff} has new maintainers (the package was
 an orphan for a few years).  As a result, new features and programs like
-@code{grn}, a preprocessor for gremlin images, and @code{grohtml}, an
-output device to produce @acronym{HTML} output, have been added.
+@code{grn}, a preprocessor for gremlin images, and an output device to
+produce @acronym{HTML} output have been added.
 
 
 @c =====================================================================
@@ -929,11 +1056,11 @@ mathematical pictures (@code{ideal}) and chemical structures
 @cindex output devices
 @cindex devices for output
 
-@code{groff} actually produces device independent code which may be fed
-into a postprocessor which will produce output for a particular device.
-Currently, @code{groff} has postprocessors for @acronym{PostScript}
-devices, character terminals, X@w{ }Windows (for previewing), @TeX{} DVI
-format, HP LaserJet@w{ }4 and Canon LBP printers (which use
+@code{groff} actually produces device independent code which may be
+fed into a postprocessor to produce output for a particular device.
+Currently, @code{groff} has postprocessors for @sc{PostScript}
+devices, character terminals, X@w{ }Windows (for previewing), @TeX{}
+DVI format, HP LaserJet@w{ }4 and Canon LBP printers (which use
 @acronym{CAPSL}), and @acronym{HTML}.
 
 
@@ -953,6 +1080,7 @@ GNU/Linux system.
 
 
 
+
 @c =====================================================================
 @c =====================================================================
 
@@ -975,9 +1103,9 @@ prefix is omitted since GNU @code{troff} is the only used incarnation of
 @code{troff}.  Exception: @code{groff} is never replaced by @code{roff}.
 
 @menu
-* Groff Options::               
-* Environment::                 
-* Invocation Examples::         
+* Groff Options::
+* Environment::
+* Invocation Examples::
 @end menu
 
 
@@ -1013,26 +1141,26 @@ grolbp}, and @ref{Invoking gxditview}.
 
 The command line format for @code{groff} is:
 
-@example
+@Example
 groff [ -abeghilpstvzCEGNRSUVXZ ] [ -F@var{dir} ] [ -m@var{name} ]
       [ -T@var{def} ] [ -f@var{fam} ] [ -w@var{name} ] [ -W@var{name} ]
       [ -M@var{dir} ] [ -d@var{cs} ] [ -r@var{cn} ] [ -n@var{num} ]
       [ -o@var{list} ] [ -P@var{arg} ] [ -L@var{arg} ] [ -I@var{dir} ]
       [ @var{files}@dots{} ]
-@end example
+@endExample
 
 The command line format for @code{gtroff} is as follows.
 
-@example
+@Example
 gtroff [ -abivzCERU ] [ -w@var{name} ] [ -W@var{name} ] [ -d@var{cs} ]
        [ -f@var{fam} ] [ -m@var{name} ] [ -n@var{num} ]
        [ -o@var{list} ] [ -r@var{cn} ] [ -T@var{name} ]
        [ -F@var{dir} ] [ -M@var{dir} ] [ @var{files}@dots{} ]
-@end example
+@endExample
 
 @noindent
-Obviously, many of the options to @code{groff} are actually passed
-on to @code{gtroff}.
+Obviously, many of the options to @code{groff} are actually passed on to
+@code{gtroff}.
 
 Options without an argument can be grouped behind a single @option{-}.
 A filename of @file{-} denotes the standard input.  It is possible to
@@ -1082,15 +1210,14 @@ accessible via @code{groff}.  This option prevents the loading of the
 Make programs run by @code{groff} print out their version number.
 
 @item -V
-Print the pipeline on stdout instead of executing it.
+Print the pipeline on @code{stdout} instead of executing it.
 
 @item -z
-Suppress output from @code{gtroff}.  Only error messages will be
-printed.
+Suppress output from @code{gtroff}.  Only error messages are printed.
 
 @item -Z
 Do not postprocess the output of @code{gtroff}.  Normally @code{groff}
-will automatically run the appropriate postprocessor.
+automatically runs the appropriate postprocessor.
 
 @item -P@var{arg}
 Pass @var{arg} to the postprocessor.  Each argument should be passed
@@ -1098,13 +1225,17 @@ with a separate @option{-P} option.  Note that @code{groff} does not
 prepend @samp{-} to @var{arg} before passing it to the postprocessor.
 
 @item -l
-Send the output to a printer.  The command used for this is specified by
-the print command in the device description file.
+Send the output to a spooler for printing.  The command used for this is
+specified by the @code{print} command in the device description file
+(see @ref{Font Files}, for more info).  If not present, @option{-l} is
+ignored.
 
 @item -L@var{arg}
 Pass @var{arg} to the spooler.  Each argument should be passed with a
 separate @option{-L} option.  Note that @code{groff} does not prepend a
-@samp{-} to @var{arg} before passing it to the postprocessor.
+@samp{-} to @var{arg} before passing it to the postprocessor.  If the
+@code{print} keyword in the device description file is missing,
+@option{-L} is ignored.
 
 @item -T@var{dev}
 Prepare output for device @var{dev}.  The default device is @samp{ps},
@@ -1113,7 +1244,7 @@ following are the output devices currently available:
 
 @table @code
 @item ps
-For @acronym{PostScript} printers and previewers.
+For @sc{PostScript} printers and previewers.
 
 @item dvi
 For @TeX{} DVI format.
@@ -1128,8 +1259,8 @@ For a 100@dmn{dpi} X11 previewer.
 For typewriter-like devices.
 
 @item latin1
-For typewriter-like devices that support the @w{Latin-1} (@w{ISO 8859-1})
-character set.
+For typewriter-like devices that support the @w{Latin-1} (@w{ISO
+8859-1}) character set.
 
 @item utf8
 For typewriter-like devices which use the Unicode (@w{ISO 10646})
@@ -1149,12 +1280,17 @@ For an HP LaserJet4-compatible (or other PCL5-compatible) printer.
 For Canon @acronym{CAPSL} printers (@w{LBP-4} and @w{LBP-8} series laser
 printers).
 
+@pindex pre-grohtml
+@pindex post-grohtml
+@cindex @code{grohtml}
 @item html
-To produce @acronym{HTML} output.
+To produce @acronym{HTML} output.  Note that the @acronym{HTML} driver
+consists of two parts, a preprocessor (@code{pre-grohtml}) and a
+postprocessor (@code{post-grohtml}).
 @end table
 
 @vindex .T
-@maindex \*(.T
+@stindex .T
 The predefined @code{gtroff} string register @code{.T} contains the
 current output device; the read-only number register @code{.T} is set
 to@w{ }1 if this option is used (which is always true if @code{groff} is
@@ -1171,16 +1307,17 @@ This is unlikely to produce good results except with @option{-Tps}.
 
 Note that this is not the same as using @option{-TX75} or
 @option{-TX100} to view a document with @code{gxditview}: The former
-will use the metrics of the specified device, whereas the latter will
-use X-specific fonts and metrics.
+uses the metrics of the specified device, whereas the latter uses
+X-specific fonts and metrics.
 
 @item -N
 Don't allow newlines with @code{eqn} delimiters.  This is the same as
 the @option{-N} option in @code{geqn}.
 
 @item -S
-Safer mode.  Pass the @option{-S} option to @code{gpic} and use the
-@option{-msafer} macros with @code{gtroff} (enabled by default).
+Safer mode.  Pass the @option{-S} option to @code{gpic} and disable the
+@code{open}, @code{opena}, @code{pso}, @code{sy}, and @code{pi}
+requests.  For security reasons, this is enabled by default.
 
 @item -U
 Unsafe mode.  Reverts to the old unsafe behaviour.
@@ -1189,7 +1326,16 @@ Unsafe mode.  Reverts to the old unsafe behaviour.
 @vindex .A
 Generate an @acronym{ASCII} approximation of the typeset output.  The
 read-only register @code{.A} is then set to@w{ }1.  @xref{Built-in
-Registers}.
+Registers}.  A typical example is
+
+@Example
+groff -a -man -Tdvi troff.man | less
+@endExample
+
+@noindent
+which shows how lines are broken for the DVI device.  Note that this
+option is rather useless today since graphic output devices are
+available virtually everywhere.
 
 @item -b
 Print a backtrace with each warning or error message.  This backtrace
@@ -1213,20 +1359,25 @@ Inhibit all error messages.
 
 @item -C
 Enable compatibility mode.  @xref{Implementation Differences}, for the
-list of incompatibilites between @code{groff} and traditional Unix
+list of incompatibilities between @code{groff} and traditional Unix
 @code{troff}.
 
 @item -d@var{cs}
 @itemx -d@var{name}=s
 Define @var{c} or @var{name} to be a string @var{s}.  @var{c} must be a
-one-letter name; @var{name} can be of arbitrary length.
+one-letter name; @var{name} can be of arbitrary length.  All string
+assignments happen before loading any macro file (including the start-up
+file).
 
 @item -f@var{fam}
-Use @var{fam} as the default font family.
+Use @var{fam} as the default font family.  @xref{Font Families}.
 
 @item -m@var{name}
-Read in the file @file{tmac.@var{name}}.  Normally this will be searched
-for in the library directory of @code{groff}.
+Read in the file @file{@var{name}.tmac}.  Normally @code{groff} searches
+for this in its macro directories.  If it isn't found, it tries
+@file{tmac.@var{name}} (and searches in the same directories).
+
+@c XXX document local and system macro dirs
 
 @item -n@var{num}
 Number the first page @var{num}.
@@ -1237,26 +1388,32 @@ Output only pages in @var{list}, which is a comma-separated list of page
 ranges; @samp{@var{n}} means print page @var{n}, @samp{@var{m}-@var{n}}
 means print every page between @var{m} and @var{n}, @samp{-@var{n}}
 means print every page up to @var{n}, @samp{@var{n}-} means print every
-page beginning with @var{n}.  @code{gtroff} will exit after printing the
+page beginning with @var{n}.  @code{gtroff} exits after printing the
 last page in the list.  All the ranges are inclusive on both ends.
 
 Within @code{gtroff}, this information can be extracted with the
 @samp{.P} register.  @xref{Built-in Registers}.
 
+If your document restarts page numbering at the beginning of each
+chapter, then @code{gtroff} prints the specified page range for each
+chapter.
+
 @item -r@var{cn}
 @itemx -r@var{name}=@var{n}
 Set number register @var{c} or @var{name} to the value @var{n}.  @var{c}
 must be a one-letter name; @var{name} can be of arbitrary length.
-@var{n} can be any @code{gtroff} numeric expression.
+@var{n} can be any @code{gtroff} numeric expression.  All register
+assignments happen before loading any macro file (including the start-up
+file).
 
 @item -F@var{dir}
 Search @file{@var{dir}} for subdirectories @file{dev@var{name}}
 (@var{name} is the name of the device), for the @file{DESC} file, and
-for font files before looking in the standard directory.
+for font files before looking in the standard directories.
 
 @item -M@var{dir}
 Search directory @file{@var{dir}} for macro files before the standard
-directory.
+directories.
 
 @item -I@var{dir}
 This option is as described in @ref{gsoelim}.  It implies the
@@ -1277,16 +1434,20 @@ not within @code{gtroff}) which can modify the behavior of @code{groff}.
 @table @code
 @item GROFF_COMMAND_PREFIX
 @tindex GROFF_COMMAND_PREFIX, environment variable
-If this is set to @var{X}, then @code{groff} will run
-@code{@var{X}troff} instead of @code{gtroff}.  This also applies to
-@code{tbl}, @code{pic}, @code{eqn}, @code{grn}, @code{refer}, and
-@code{soelim}.  It does not apply to @code{grops}, @code{grodvi},
-@code{grotty}, @code{grohtml}, @code{grolj4}, and @code{gxditview}.
+If this is set to @var{X}, then @code{groff} runs @code{@var{X}troff}
+instead of @code{gtroff}.  This also applies to @code{tbl}, @code{pic},
+@code{eqn}, @code{grn}, @code{refer}, and @code{soelim}.  It does not
+apply to @code{grops}, @code{grodvi}, @code{grotty}, @code{pre-grohtml},
+@code{post-grohtml}, @code{grolj4}, and @code{gxditview}.
+
+@c XXX document default values
 
 @item GROFF_TMAC_PATH
 @tindex GROFF_TMAC_PATH, environment variable
-A colon-separated list of directories in which to search for macro
-files.
+A colon-separated list of directories in which to search for macro files
+(before the default directories are tried).
+
+@c XXX document local and system macro dirs
 
 @item GROFF_TYPESETTER
 @tindex GROFF_TYPESETTER, environment variable
@@ -1295,21 +1456,23 @@ The default output device.
 @item GROFF_FONT_PATH
 @tindex GROFF_FONT_PATH, environment variable
 A colon-separated list of directories in which to search for the
-@code{dev}@var{name} directory.
+@code{dev}@var{name} directory (before the default directories are
+tried).
 
-@item PATH
-@tindex PATH, environment variable
-The search path for commands executed by @code{groff}.
+@item GROFF_BIN_PATH
+@tindex GROFF_BIN_PATH, environment variable
+This search path, followed by @code{PATH}, is used for commands executed
+by @code{groff}.
 
 @item GROFF_TMPDIR
 @tindex GROFF_TMPDIR, environment variable
 @tindex TMPDIR, environment variable
-The directory in which temporary files will be created.  If this is not
-set and @env{TMPDIR} is set, temporary files will be created in that
-directory.  Otherwise temporary files will be created in a
-system-dependent default directory (on Unix and GNU/Linux systems, this
-is usually @file{/tmp}).  The @code{grops} and @code{grefer} commands
-can create temporary files in this directory.
+The directory in which @code{groff} creates temporary files.  If this is
+not set and @env{TMPDIR} is set, temporary files are created in that
+directory.  Otherwise temporary files are created in a system-dependent
+default directory (on Unix and GNU/Linux systems, this is usually
+@file{/tmp}).  @code{grops}, @code{grefer}, @code{pre-grohtml}, and
+@code{post-grohtml} can create temporary files in this directory.
 @end table
 
 Note that MS-DOS and MS-Windows ports of @code{groff} use semi-colons,
@@ -1324,33 +1487,33 @@ above.
 @cindex invocation examples
 @cindex examples of invocation
 
-This section will list several common uses of @code{groff} and the
-command line which will accomplish it.
+This section lists several common uses of @code{groff} and the
+corresponding command lines.
 
-@example
+@Example
 groff file
-@end example
+@endExample
 
 @noindent
 This command processes @file{file} without a macro package or a
 preprocessor.  The output device is the default, @samp{ps}, and the
-output is sent to stdout.
+output is sent to @code{stdout}.
 
-@example
+@Example
 groff -t -mandoc -Tascii file | less
-@end example
+@endExample
 
 @noindent
-This is basically what a call to the @code{man} program does.  The
-manual page @file{file} is processed with the @file{mandoc} macros
-(which in turn either calls the @file{man} or the @file{mdoc} macro
-package), using the @code{tbl} preprocessor and the @acronym{ASCII}
-output device.  Finally, the result is displayed with the @code{less}
-pager.
-
-@example
+This is basically what a call to the @code{man} program does.
+@code{gtroff} processes the manual page @file{file} with the
+@file{mandoc} macro file (which in turn either calls the @file{man} or
+the @file{mdoc} macro package), using the @code{tbl} preprocessor and
+the @acronym{ASCII} output device.  Finally, the @code{less} pager
+displays the result.
+
+@Example
 groff -X -m me file
-@end example
+@endExample
 
 @noindent
 Preview @file{file} with @code{gxditview}, using the @file{me} macro
@@ -1360,52 +1523,57 @@ device (@samp{ps}).  Note that you can either say @w{@samp{-m me}} or
 @acronym{UNIX}.@footnote{The same is true for the other main macro
 packages that come with @code{groff}: @file{man}, @file{mdoc},
 @file{ms}, @file{mm}, and @file{mandoc}.  This won't work in general;
-for example, to load @file{tmac.safer}, either @samp{-msafer} or
-@w{@samp{-m safer}} must be used.}
+for example, to load @file{trace.tmac}, either @samp{-mtrace} or
+@w{@samp{-m trace}} must be used.}
 
-@example
+@Example
 groff -man -rD1 -z file
-@end example
+@endExample
 
 @noindent
 Check @file{file} with the @file{man} macro package, forcing
 double-sided printing -- don't produce any output.
 
-@c ---------------------------------------------------------------------
-
 @menu
-* grog::                        
+* grog::
 @end menu
 
+@c ---------------------------------------------------------------------
+
 @node grog,  , Invocation Examples, Invocation Examples
 @subsection @code{grog}
 
 @pindex grog
 @code{grog} reads files, guesses which of the @code{groff} preprocessors
 and/or macro packages are required for formatting them, and prints the
-@code{groff} command including those options on the standard output.
-The options generated are one of @option{-e}, @option{-man},
-@option{-me}, @option{-mm}, @option{-ms}, @option{-p}, @option{-R},
-@option{-g}, @option{-G}, @option{-s}, and @option{-t}.
+@code{groff} command including those options on the standard output.  It
+generates one or more of the options @option{-e}, @option{-man},
+@option{-me}, @option{-mm}, @option{-ms}, @option{-mdoc},
+@option{-mdoc-old}, @option{-p}, @option{-R}, @option{-g}, @option{-G},
+@option{-s}, and @option{-t}.
+
+A special file name @file{-} refers to the standard input.  Specifying
+no files also means to read the standard input.  Any specified options
+are included in the printed command.  No space is allowed between
+options and their arguments.  The only options recognized are
+@option{-C} (which is also passed on) to enable compatibility mode, and
+@option{-v} (if it is the only parameter) to print the version number.
 
-A special file name @file{-} is taken to refer to the standard input.
-If no files are specified the standard input will be read.  Any
-specified options will be included in the printed command.  No space is
-allowed between options and their arguments.  For example,
+For example,
 
-@example
+@Example
 grog -Tdvi paper.ms
-@end example
+@endExample
 
 @noindent
-will guess the appropriate command to print @file{paper.ms} and then
-print it to the command line after adding the @option{-Tdvi} option.
-For direct execution, enclose the call to @code{grog} in backquotes at
-the @acronym{UNIX} shell prompt:
+guesses the appropriate command to print @file{paper.ms} and then prints
+it to the command line after adding the @option{-Tdvi} option.  For
+direct execution, enclose the call to @code{grog} in backquotes at the
+@acronym{UNIX} shell prompt:
 
-@example
+@Example
 `grog -Tdvi paper.ms` > paper.dvi
-@end example
+@endExample
 
 @noindent
 As seen in the example, it is still necessary to redirect the output to
@@ -1430,8 +1598,8 @@ people.  This chapter covers the material needed to efficiently use a
 macro package.
 
 @menu
-* Basics::                      
-* Common Features::             
+* Basics::
+* Common Features::
 @end menu
 
 
@@ -1458,39 +1626,39 @@ The word @dfn{argument} is used in this chapter to mean a word or number
 which appears on the same line as a request, and which modifies the
 meaning of that request.  For example, the request
 
-@example
+@Example
 .sp
-@end example
+@endExample
 
 @noindent
 spaces one line, but
 
-@example
+@Example
 .sp 4
-@end example
+@endExample
 
 @noindent
 spaces four lines.  The number@w{ }4 is an argument to the @code{sp}
 request which says to space four lines instead of one.  Arguments are
-separated from the request and from each other by spaces.  More details
-on this can be found in @ref{Request Arguments}.
+separated from the request and from each other by spaces (@emph{no}
+tabs).  More details on this can be found in @ref{Request Arguments}.
 
 The primary function of @code{gtroff} is to collect words from input
 lines, fill output lines with those words, justify the right-hand margin
 by inserting extra spaces in the line, and output the result.  For
 example, the input:
 
-@example
+@Example
 Now is the time
 for all good men
 to come to the aid
 of their party.
 Four score and seven
 years ago,...
-@end example
+@endExample
 
 @noindent
-will be read, packed onto output lines, and justified to produce:
+is read, packed onto output lines, and justified to produce:
 
 @quotation
 Now is the time for all good men to come to the aid of their party.
@@ -1502,63 +1670,78 @@ Four score and seven years ago,...
 Sometimes a new output line should be started even though the current
 line is not yet full; for example, at the end of a paragraph.  To do
 this it is possible to cause a @dfn{break}, which starts a new output
-line.  Some requests cause a break automatically, as do blank input
-lines and input lines beginning with a space.
+line.  Some requests cause a break automatically, as normally do blank
+input lines and input lines beginning with a space.
 
-Not all input lines are text to be formatted.  Some of the input lines
-are requests which describe how to format the text.  Requests always
-have a period (@samp{.}) or an apostrophe (@samp{'}) as the first
-character of the input line.
+Not all input lines are text to be formatted.  Some input lines are
+requests which describe how to format the text.  Requests always have a
+period (@samp{.}) or an apostrophe (@samp{'}) as the first character of
+the input line.
 
 The text formatter also does more complex things, such as automatically
 numbering pages, skipping over page boundaries, putting footnotes in the
 correct place, and so forth.
 
 Here are a few hints for preparing text for input to @code{gtroff}.
+
+@itemize @bullet
+@item
 First, keep the input lines short.  Short input lines are easier to
-edit, and @code{gtroff} will pack words onto longer lines anyhow.  In
-keeping with this, it is helpful to begin a new line after every period,
-comma, or phrase, since common corrections are to add or delete
-sentences or phrases.  Secondly, do not hyphenate words at the end of
-lines -- @code{gtroff} is smart enough to hyphenate words for the user
-as needed, but is not smart enough to take hyphens out and join a word
-back together.  Also, words such as ``mother-in-law'' should not be
-broken over a line, since then a space can occur where not wanted, such
-as ``@w{mother- in}-law''.
-
-@findex ls
+edit, and @code{gtroff} packs words onto longer lines anyhow.
+
+@item
+In keeping with this, it is helpful to begin a new line after every
+comma or phrase, since common corrections are to add or delete sentences
+or phrases.
+
+@item
+End each sentence with two spaces -- or better, start each sentence on a
+new line.  @code{gtroff} recognizes characters that usually end a
+sentence, and inserts sentence space accordingly.
+
+@item
+Do not hyphenate words at the end of lines -- @code{gtroff} is smart
+enough to hyphenate words as needed, but is not smart enough to take
+hyphens out and join a word back together.  Also, words such as
+``mother-in-law'' should not be broken over a line, since then a space
+can occur where not wanted, such as ``@w{mother- in}-law''.
+@end itemize
+
+@rqindex ls
 @cindex double spacing
 @cindex spacing
-@code{gtroff} will double space output text automatically if you use the
-request @w{@samp{.ls 2}}.  Single spaced mode can be reactivated by
-typing @w{@samp{.ls 1}}.
+@code{gtroff} double spaces output text automatically if you use the
+request @w{@samp{.ls 2}}.  Reactivate single spaced mode by typing
+@w{@samp{.ls 1}}.
 
-A number of requests allow to change the way the output looks, sometimes
-called the @dfn{layout} of the output page.  Most of these requests
-adjust the placing of @dfn{white space} (blank lines or spaces).
+A number of requests allow to change the way the output looks,
+sometimes called the @dfn{layout} of the output page.  Most of these
+requests adjust the placing of @dfn{white space} (blank lines or
+spaces).
 
 @cindex new page
 The @samp{.bp} request starts a new page, causing a line break.
 
-@cindex blank lines
-@cindex empty lines
-@cindex lines, empty
+@cindex blank line
+@cindex empty line
+@cindex line, empty
 The request @w{@samp{.sp @var{N}}} leaves @var{N}@w{ }lines of blank
 space.  @var{N}@w{ }can be omitted (meaning skip a single line) or can
 be of the form @var{N}i (for @var{N}@w{ }inches) or @var{N}c (for
 @var{N}@w{ }centimeters).  For example, the input:
 
-@example
+@Example
 .sp 1.5i
 My thoughts on the subject
 .sp
-@end example
+@endExample
 
 @noindent
 leaves one and a half inches of space, followed by the line ``My
-thoughts on the subject'', followed by a single blank line.
+thoughts on the subject'', followed by a single blank line (more
+measurement units are available, see @ref{Measurements}).
 
-@findex ce
+@rqindex ce
 @cindex centering lines
 @cindex lines, centering
 Text lines can be centered by using the @code{ce} request.  The line
@@ -1567,17 +1750,17 @@ than one line, use @w{@samp{.ce @var{N}}} (where @var{N} is the number
 of lines to center), followed by the @var{N}@w{ }lines.  To center many
 lines without counting them, type:
 
-@example
+@Example
 .ce 1000
 lines to center
 .ce 0
-@end example
+@endExample
 
 @noindent
 The @w{@samp{.ce 0}} request tells @code{groff} to center zero more
 lines, in other words, stop centering.
 
-@findex br
+@rqindex br
 @cindex line break
 @cindex break
 All of these requests cause a break; that is, they always start a new
@@ -1592,7 +1775,7 @@ line.  To start a new line without performing any other action, use
 @cindex common features
 @cindex features, common
 
-@code{gtroff} provides very low level operations for formatting a
+@code{gtroff} provides very low-level operations for formatting a
 document.  There are many common routine operations which are done in
 all documents.  These common operations are written into @dfn{macros}
 and collected into a @dfn{macro package}.
@@ -1600,55 +1783,59 @@ and collected into a @dfn{macro package}.
 All macro packages provide certain common capabilities which fall into
 the following categories.
 
-@c ---------------------------------------------------------------------
-
 @menu
-* Paragraphs::                  
-* Sections and Chapters::       
-* Headers and Footers::         
-* Page Layout Adjustment::      
-* Displays::                    
-* Footnotes and Annotations::   
-* Table of Contents::           
-* Indices::                     
-* Paper Formats::               
-* Multiple Columns::            
-* Font and Size Changes::       
-* Predefined Strings::          
-* Preprocessor Support::        
-* Configuration and Customization::  
+* Paragraphs::
+* Sections and Chapters::
+* Headers and Footers::
+* Page Layout Adjustment::
+* Displays::
+* Footnotes and Annotations::
+* Table of Contents::
+* Indices::
+* Paper Formats::
+* Multiple Columns::
+* Font and Size Changes::
+* Predefined Strings::
+* Preprocessor Support::
+* Configuration and Customization::
 @end menu
 
+@c ---------------------------------------------------------------------
+
 @node Paragraphs, Sections and Chapters, Common Features, Common Features
 @subsection Paragraphs
 @cindex paragraphs
 
-One of the most common and most used capability is starting a paragraph.
-There are a number of different types of paragraphs, any of which can be
-initiated with macros supplied by the macro package.  Normally,
-paragraphs start with a blank line and the first line indented, like the
-text in this manual.  There are also block style paragraphs, which omit
-the indentation:
+One of the most common and most used capability is starting a
+paragraph.  There are a number of different types of paragraphs, any
+of which can be initiated with macros supplied by the macro package.
+Normally, paragraphs start with a blank line and the first line
+indented, like the text in this manual.  There are also block style
+paragraphs, which omit the indentation:
 
-@example
+@Example
 Some   men  look   at  constitutions   with  sanctimonious
 reverence, and deem them like the ark of the covenant, too
 sacred to be touched.
-@end example
+@endExample
 
 @noindent
 And there are also indented paragraphs which begin with a tag or label
 at the margin and the remaining text indented.
 
 @example
+@group
 one   This is  the first paragraph.  Notice  how the first
       line of  the resulting  paragraph lines up  with the
       other lines in the paragraph.
+@end group
+@group
 longlabel
       This  paragraph   had  a  long   label.   The  first
-      character of text on the first line will not line up
+      character of text on the first line does not line up
       with  the  text  on  second  and  subsequent  lines,
-      although they will line up with each other.
+      although they line up with each other.
+@end group
 @end example
 
 A variation of this is a bulleted list.
@@ -1671,10 +1858,9 @@ supply macros for starting chapters and appendices.
 @node Headers and Footers, Page Layout Adjustment, Sections and Chapters, Common Features
 @subsection Headers and Footers
 
-Every macro package gives some way to manipulate the headers and
-footers (or @dfn{titles}) on each page.  Some packages will allow for
-different ones on the even and odd pages (for material printed in a book
-form).
+Every macro package gives some way to manipulate the headers and footers
+(or @dfn{titles}) on each page.  Some packages allow for different ones
+on the even and odd pages (for material printed in a book form).
 
 The titles are called three-part titles, that is, there is a
 left-justified part, a centered part, and a right-justified part.  An
@@ -1713,17 +1899,16 @@ used in this paper.
 @cindex keep
 A @dfn{keep} is a display of lines which are kept on a single page if
 possible.  An example for a keep might be a diagram.  Keeps differ from
-lists in that lists may be broken over a page boundary whereas keeps
-will not.
+lists in that lists may be broken over a page boundary whereas keeps are
+not.
 
 @cindex keep, floating
 @cindex floating keep
 Floating keeps move relative to the text.  Hence, they are good for
-things which will be referred to by name, such as ``See figure@w{ }3''.
-A floating keep will appear at the bottom of the current page if it will
-fit; otherwise, it will appear at the top of the next page.  Meanwhile,
-the surrounding text will `flow' around the keep, thus leaving now blank
-areas.
+things which are referred to by name, such as ``See figure@w{ }3''.  A
+floating keep appears at the bottom of the current page if it fits;
+otherwise, it appears at the top of the next page.  Meanwhile, the
+surrounding text `flows' around the keep, thus leaving no blank areas.
 
 @c ---------------------------------------------------------------------
 
@@ -1755,9 +1940,9 @@ of automatically numbering either type of annotation.
 @dfn{Tables of contents} are a type of delayed text having a tag
 (usually the page number) attached to each entry after a row of dots.
 The table accumulates throughout the paper until printed, usually after
-the paper has ended.  Many macro packages will provide the ability to
-have several tables of contents (i.e.@: one standard one, one for
-tables, etc).
+the paper has ended.  Many macro packages provide the ability to have
+several tables of contents (e.g.@: a standard table of contents, a list
+of tables, etc).
 
 @c ---------------------------------------------------------------------
 
@@ -1765,7 +1950,7 @@ tables, etc).
 @subsection Indices
 @cindex index, in macro package
 
-While some macro packages will use the term @dfn{index}, none actually
+While some macro packages use the term @dfn{index}, none actually
 provide that functionality.  The facilities they call indices are
 actually more appropriate for tables of contents.
 
@@ -1810,23 +1995,30 @@ various special characters.
 @node Preprocessor Support, Configuration and Customization, Predefined Strings, Common Features
 @subsection Preprocessor Support
 
-All macro packages provide support for the various preprocessors.
+All macro packages provide support for the various preprocessors and may
+extend their functionality.
+
+For example, all macro packages mark tables (which are processed with
+@code{gtbl}) by placing them between @code{.TS} and @code{.TE} macros.
+The @file{ms} macro package has an option, @code{.TS@w{}H}, that prints
+a caption at the top of a new page (when the table is too long to fit on
+a single page).
 
 @c ---------------------------------------------------------------------
 
 @node Configuration and Customization,  , Preprocessor Support, Common Features
 @subsection Configuration and Customization
 
-Some macro packages provide means of customizing many of the details of how
-the package behaves.  This ranges from setting the default type size to
-changing the appearance of section headers.
+Some macro packages provide means of customizing many of the details of
+how the package behaves.  This ranges from setting the default type size
+to changing the appearance of section headers.
 
 
 
 @c =====================================================================
 @c =====================================================================
 
-@node Macro Packages, Programming Tutorial, Tutorial for Macro Users, Top
+@node Macro Packages, gtroff Reference, Tutorial for Macro Users, Top
 @chapter Macro Packages
 @cindex macro packages
 @cindex packages, macros
@@ -1835,11 +2027,11 @@ This chapter documents the main macro packages that come with
 @code{groff}.
 
 @menu
-* man::                         
-* mdoc::                        
-* ms::                          
-* me::                          
-* mm::                          
+* man::
+* mdoc::
+* ms::
+* me::
+* mm::
 @end menu
 
 
@@ -1849,18 +2041,21 @@ This chapter documents the main macro packages that come with
 @section @file{man}
 @cindex @file{man}
 @cindex manual pages
-@pindex tmac.an
-@pindex tmac.man
+@pindex an.tmac
+@pindex man.tmac
+@pindex man-old.tmac
 
 This is the most popular and probably the most important macro package
 of @code{groff}.  It is easy to use, and a vast majority of manual pages
 are based on it.
 
 @menu
-* Man options::                 
-* Man usage::                   
-* Man font macros::             
-* Miscellaneous man stuff::     
+* Man options::
+* Man usage::
+* Man font macros::
+* Miscellaneous man macros::
+* Predefined man strings::
+* Preprocessors in man pages::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -1871,16 +2066,20 @@ are based on it.
 The command line format for using the @file{man} macros with
 @code{groff} is:
 
-@c XXX document @TMAC_AN_PREFIX@
-
-@example
-groff -m man [ -rC1 ] [ -rD1 ] [ -rP@var{nnn} ] [ -rS@var{xx} ]
-      [ -rX@var{nnn} ] [ @var{files}@dots{} ] 
-@end example
+@Example
+groff -m man [ -rcR=1 ] [ -rC1 ] [ -rD1 ] [ -rP@var{nnn} ]
+      [ -rS@var{xx} ] [ -rX@var{nnn} ] [ @var{files}@dots{} ]
+@endExample
 
+@noindent
 It is possible to use @samp{-man} instead of @w{@samp{-m man}}.
 
 @table @code
+@item -rcR=1
+This option (the default if a tty output device is used) creates a
+single, very long page instead of multiple pages.  Use @code{-rcR=0}
+to disable it.
+
 @item -rC1
 If more than one manual page is given on the command line, number the
 pages continuously, rather than starting each at@w{ }1.
@@ -1890,7 +2089,7 @@ Double-sided printing.  Footers for even and odd pages are formatted
 differently.
 
 @item -rP@var{nnn}
-Enumeration of pages will start with @var{nnn} rather than with@w{ }1.
+Page numbering starts with @var{nnn} rather than with@w{ }1.
 
 @item -rS@var{xx}
 Use @var{xx} (which can be 10, 11, or@w{ }12@dmn{pt}) as the base
@@ -1898,7 +2097,7 @@ document font size instead of the default value of@w{ }10@dmn{pt}.
 
 @item -rX@var{nnn}
 After page @var{nnn}, number pages as @var{nnn}a, @var{nnn}b,
-@var{nnn}c, etc.  For example, the option @option{-rX2} will produce the
+@var{nnn}c, etc.  For example, the option @option{-rX2} produces the
 following page numbers: 1, 2, 2a, 2b, 2c, etc.
 @end table
 
@@ -1912,22 +2111,22 @@ following page numbers: 1, 2, 2a, 2b, 2c, etc.
 @pindex man.local
 This section describes the available macros for manual pages.  For
 further customization, put additional macros and requests into the file
-@file{man.local} which will be loaded immediately after @file{tmac.an}.
+@file{man.local} which is loaded immediately after the @file{man}
+package.
 
-@maindex TH
-@Defmac{TH, title section [@var{extra1}] [@var{extra2}] [@var{extra3}]}
-Sets the title of the man page to @var{title} and the section to
+@Defmac {TH, title section [@Var{extra1}] [@Var{extra2}] [@Var{extra3}]}
+Set the title of the man page to @var{title} and the section to
 @var{section}, which must have a value between 1 and@w{ }8.  The value
-of @var{section} may also have a string appended, e.g.@: @samp{.pm}, to
-indicate a specific subsection of the man pages.
+of @var{section} may also have a string appended, e.g.@: @samp{.pm},
+to indicate a specific subsection of the man pages.
 
 Both @var{title} and @var{section} are positioned at the left and right
 in the header line (with @var{section} in parentheses immediately
-appended to @var{title}.  @var{extra1} will be positioned in the middle
-of the footer line.  @var{extra2} will be positioned at the left in the
-footer line (resp.@: at the left on even pages and at the right on odd
-pages if double-sided printing is active).  @var{extra3} is centered in
-the header line.
+appended to @var{title}.  @var{extra1} is positioned in the middle of
+the footer line.  @var{extra2} is positioned at the left in the footer
+line (or at the left on even pages and at the right on odd pages if
+double-sided printing is active).  @var{extra3} is centered in the
+header line.
 
 For @acronym{HTML} output, headers and footers are completely suppressed.
 
@@ -1936,100 +2135,91 @@ again (except if the @option{-rC1} option is given on the command line)
 -- this feature is intended only for formatting multiple man pages; a
 single man page should contain exactly one @code{TH} macro at the
 beginning of the file.
-@end_Defmac
+@endDefmac
 
-@maindex SH
-@Defmac{SH, [@var{heading}]}
-Sets up an unnumbered section heading sticking out to the left.  Prints
-out all the text following @code{SH} up to the end of the line (resp.@:
-the text in the next line if there is no argument to @code{SH}) in bold
+@Defmac {SH, [@Var{heading}]}
+Set up an unnumbered section heading sticking out to the left.  Prints
+out all the text following @code{SH} up to the end of the line (or the
+text in the next line if there is no argument to @code{SH}) in bold
 face, one size larger than the base document size.  Additionally, the
 left margin for the following text is reset to its default value.
-@end_Defmac
+@endDefmac
 
-@maindex SS
-@Defmac{SS, [@var{heading}]}
-Sets up an unnumbered section heading.  Prints out all the text
-following @code{SS} up to the end of the line (resp.@: the text in the
-next line if there is no argument to @code{SS}) in bold face, at the
-same size as the base document size.  Additionally, the left margin for
-the following text is reset to its default value.
-@end_Defmac
+@Defmac {SS, [@Var{heading}]}
+Set up an unnumbered (sub)section heading.  Prints out all the text
+following @code{SS} up to the end of the line (or the text in the next
+line if there is no argument to @code{SS}) in bold face, at the same
+size as the base document size.  Additionally, the left margin for the
+following text is reset to its default value.
+@endDefmac
 
-@maindex TP
-@Defmac{TP, [@var{nnn}]}
-Sets up an indented paragraph with label.  The indentation is set to
-@var{nnn} if that argument is supplied (the default unit is @samp{n} if
-omitted), otherwise it is set to the default indentation value.
+@Defmac {TP, [@Var{nnn}]}
+Set up an indented paragraph with label.  The indentation is set to
+@var{nnn} if that argument is supplied (the default unit is @samp{n}
+if omitted), otherwise it is set to the default indentation value.
 
 The first line of text following this macro is interpreted as a string
 to be printed flush-left, as it is appropriate for a label.  It is not
 interpreted as part of a paragraph, so there is no attempt to fill the
 first line with text from the following input lines.  Nevertheless, if
 the label is not as wide as the indentation, then the paragraph starts
-at the same line (but indented), continuing on the following lines.  If
-the label is wider than the indentation, then the descriptive part of
-the paragraph begins on the line following the label, entirely indented.
-Note that neither font shape nor font size of the label is set to a
-default value; on the other hand, the rest of the text will have default
-font settings.
-@end_Defmac
-
-@maindex LP
-@maindex PP
-@maindex P
-@Defmac{LP}
-@Defmacx{PP}
-@Defmacx{P}
-These macros are mutual aliases.  Any of them causes a line break at the
-current position, followed by a vertical space downwards by the amount
-specified by the @code{PD} macro.  The font size and shape are reset to
-the default value (10@dmn{pt} resp.@: Roman).  Finally, the current left
-margin is restored.
-@end_Defmac
-
-@maindex IP
-@Defmac{IP, [@var{designator}] [@var{nnn}]}
-Sets up an indented paragraph, using @var{designator} as a tag to mark
-its beginning.  The indentation is set to @var{nnn} if that argument is
-supplied (default unit is @samp{n}), otherwise the default indentation
-value is used.  Font size and face of the paragraph (but not the
-designator) are reset to their default values.  To start an indented
-paragraph with a particular indentation but without a designator, use
-@samp{""} (two double quotes) as the first argument of @code{IP}.
+at the same line (but indented), continuing on the following lines.
+If the label is wider than the indentation, then the descriptive part
+of the paragraph begins on the line following the label, entirely
+indented.  Note that neither font shape nor font size of the label is
+set to a default value; on the other hand, the rest of the text has
+default font settings.
+@endDefmac
+
+@Defmac {LP}
+@Defmacx {PP}
+@Defmacx {P}
+These macros are mutual aliases.  Any of them causes a line break at
+the current position, followed by a vertical space downwards by the
+amount specified by the @code{PD} macro.  The font size and shape are
+reset to the default value (10@dmn{pt} roman).  Finally, the current
+left margin is restored.
+@endDefmac
+
+@Defmac {IP, [@Var{designator}] [@Var{nnn}]}
+Set up an indented paragraph, using @var{designator} as a tag to mark
+its beginning.  The indentation is set to @var{nnn} if that argument
+is supplied (default unit is @samp{n}), otherwise the default
+indentation value is used.  Font size and face of the paragraph (but
+not the designator) are reset to their default values.  To start an
+indented paragraph with a particular indentation but without a
+designator, use @samp{""} (two double quotes) as the first argument of
+@code{IP}.
 
 For example, to start a paragraph with bullets as the designator and
 4@dmn{en} indentation, write
 
-@example
+@Example
 .IP \(bu 4
-@end example
-@end_Defmac
+@endExample
+@endDefmac
 
-@maindex HP
 @cindex hanging indentation, in manual pages
-@Defmac{HP, [@var{nnn}]}
-Sets up a paragraph with hanging left indentation.  The indentation is
+@Defmac {HP, [@Var{nnn}]}
+Set up a paragraph with hanging left indentation.  The indentation is
 set to @var{nnn} if that argument is supplied (default unit is
 @samp{n}), otherwise the default indentation value is used.  Font size
 and face are reset to their default values.
-@end_Defmac
+@endDefmac
 
-@maindex RS
 @cindex left margin, how to move, in manual pages
-@Defmac{RS, [@var{nnn}]}
-This macro moves the left margin to the right by the value @var{nnn} if
-specified (default unit is @samp{n}); otherwise the default indentation
-value is used.  Calls to the @code{RS} macro can be nested.
-@end_Defmac
-
-@maindex RE
-@Defmac{RE, [@var{nnn}]}
-This macro moves the left margin back to level @var{nnn}; if no argument
-is given, it moves one level back.  The first level (i.e., no call to
-@code{RS} yet) has number@w{ }1, and each call to @code{RS} increases
-the level by@w{ }1.
-@end_Defmac
+@Defmac {RS, [@Var{nnn}]}
+Move the left margin to the right by the value @var{nnn} if specified
+(default unit is @samp{n}); otherwise the default indentation value is
+used.  Calls to the @code{RS} macro can be nested.
+@endDefmac
+
+@Defmac {RE, [@Var{nnn}]}
+Move the left margin back to level @var{nnn}; if no argument is given,
+it moves one level back.  The first level (i.e., no call to @code{RS}
+yet) has number@w{ }1, and each call to @code{RS} increases the level
+by@w{ }1.
+@endDefmac
 
 @maindex SH
 @maindex SS
@@ -2051,121 +2241,101 @@ vertical space.
 
 @c ---------------------------------------------------------------------
 
-@node Man font macros, Miscellaneous man stuff, Man usage, man
+@node Man font macros, Miscellaneous man macros, Man usage, man
 @subsection Macros to set fonts
 @cindex fonts in manual pages
 @cindex @code{man}, how to set fonts
 
-The standard font is Roman; the default text size is 10@w{ }point.
+The standard font is roman; the default text size is 10@w{ }point.
 
-@maindex SM
-@Defmac{SM, [@var{text}]}
-Causes the text on the same line or the text on the next line to appear
-in a font that is one point size smaller than the default font.
-@end_Defmac
+@Defmac {SM, [@Var{text}]}
+Set the text on the same line or the text on the next line in a font
+that is one point size smaller than the default font.
+@endDefmac
 
-@maindex SB
 @cindex boldface, in manual pages
-@Defmac{SB, [@var{text}]}
-Causes the text on the same line or the text on the next line to appear
-in boldface font, one point size smaller than the default font.
-@end_Defmac
+@Defmac {SB, [@Var{text}]}
+Set the text on the same line or the text on the next line in boldface
+font, one point size smaller than the default font.
+@endDefmac
 
-@maindex BI
-@Defmac{BI, text}
-Causes text on the same line to appear alternately in bold face and
-italic.  The text must be on the same line as the macro call.  Thus,
+@Defmac {BI, text}
+Set its arguments alternately in bold face and italic.  Thus,
 
-@example
+@Example
 .BI this "word and" that
-@end example
+@endExample
 
 @noindent
-would cause ``this'' and ``that'' to appear in bold face, while ``word
-and'' appears in italics.
-@end_Defmac
-
-@maindex IB
-@Defmac{IB, text}
-Causes text to appear alternately in italic and bold face.  The text
-must be on the same line as the macro call.
-@end_Defmac
-
-@maindex RI
-@Defmac{RI, text}
-Causes text on the same line to appear alternately in roman and italic.
-The text must be on the same line as the macro call.
-@end_Defmac
-
-@maindex IR
-@Defmac{IR, text}
-Causes text on the same line to appear alternately in italic and roman.
-The text must be on the same line as the macro call.
-@end_Defmac
-
-@maindex BR
-@Defmac{BR, text}
-Causes text on the same line to appear alternately in bold face and
-roman.  The text must be on the same line as the macro call.
-@end_Defmac
-
-@maindex RB
-@Defmac{RB, text}
-Causes text on the same line to appear alternately in roman and bold
-face.  The text must be on the same line as the macro call.
-@end_Defmac
-
-@maindex R
-@Defmac{R, [@var{text}]}
-Causes @var{text} to appear in roman font.  If no text is present on the
-line where the macro is called, then the text of the next line appears
-in roman.  This is the default font to which text is returned at the end
-of processing of the other macros.
-@end_Defmac
-
-@maindex B
-@Defmac{B, [@var{text}]}
-Causes @var{text} to appear in bold face.  If no text is present on the
-line where the macro is called, then the text of the next line appears
-in bold face.
-@end_Defmac
-
-@maindex I
+would set ``this'' and ``that'' in bold face, and ``word and'' in
+italics.
+@endDefmac
+
+@Defmac {IB, text}
+Set its arguments alternately in italic and bold face.
+@endDefmac
+
+@Defmac {RI, text}
+Set its arguments alternately in roman and italic.
+@endDefmac
+
+@Defmac {IR, text}
+Set its arguments alternately in italic and roman.
+@endDefmac
+
+@Defmac {BR, text}
+Set its arguments alternately in bold face and roman.
+@endDefmac
+
+@Defmac {RB, text}
+Set its arguments alternately in roman and bold face.
+@endDefmac
+
+@Defmac {R, [@Var{text}]}
+Set @var{text} in roman font.  If no text is present on the line where
+the macro is called, then the text of the next line appears in roman.
+This is the default font to which text is returned at the end of
+processing of the other macros.
+@endDefmac
+
+@Defmac {B, [@Var{text}]}
+Set @var{text} in bold face.  If no text is present on the line where
+the macro is called, then the text of the next line appears in bold
+face.
+@endDefmac
+
 @cindex italic, in manual pages
-@Defmac{I, [@var{text}]}
-Causes @var{text} to appear in italic.  If no text is present on the
-line where the macro is called, then the text of the next line appears
-in italic.
-@end_Defmac
+@Defmac {I, [@Var{text}]}
+Set @var{text} in italic.  If no text is present on the line where the
+macro is called, then the text of the next line appears in italic.
+@endDefmac
 
 @c ---------------------------------------------------------------------
 
-@node Miscellaneous man stuff,  , Man font macros, man
-@subsection Miscellaneous
+@node Miscellaneous man macros, Predefined man strings, Man font macros, man
+@subsection Miscellaneous macros
 
 @pindex grohtml
 @cindex @file{man}, default indentation
 @cindex default indentation, @file{man}
 The default indentation is 7.2@dmn{n} for all output devices except for
-@code{grohtml} which uses 1.2@dmn{i} instead.
+@code{grohtml} which ignores indentation.
 
-@maindex DT
 @maindex TH
 @cindex tab stops, in manual pages
-@Defmac{DT}
-Sets tabs every 0.5@w{ }inches.  Since this macro is always called
+@Defmac {DT}
+Set tabs every 0.5@w{ }inches.  Since this macro is always called
 during a @code{TH} request, it makes sense to call it only if the tab
 positions have been changed.
-@end_Defmac
+@endDefmac
 
-@maindex PD
 @cindex empty space before a paragraph, in manual pages
-@Defmac{PD, [@var{nnn}]}
-Adjusts the empty space before a new paragraph (resp.@: section).  The
-optional argument gives the amount of space (default units are
+@Defmac {PD, [@Var{nnn}]}
+Adjust the empty space before a new paragraph (or section).  The
+optional argument gives the amount of space (default unit is
 @samp{v}); without parameter, the value is reset to its default value
 (1@w{ }line for tty devices, 0.4@dmn{v}@w{ }otherwise).
-@end_Defmac
+@endDefmac
 
 @maindex SH
 @maindex SS
@@ -2175,35 +2345,40 @@ optional argument gives the amount of space (default units are
 @maindex P
 @maindex IP
 @maindex HP
-This affects the macros @code{SH}, @code{SS}, @code{TP}, @code{LP}
-(resp.@: @code{PP} and @code{P}), @code{IP}, and @code{HP}.
+This affects the macros @code{SH}, @code{SS}, @code{TP}, @code{LP} (as
+well as @code{PP} and @code{P}), @code{IP}, and @code{HP}.
+
+@c ---------------------------------------------------------------------
+
+@node Predefined man strings, Preprocessors in man pages, Miscellaneous man macros, man
+@subsection Predefined strings
 
 The following strings are defined:
 
-@maindex \*S
-@Defmac{\\*S}
+@Defstr {*S}
 Switch back to the default font size.
-@end_Defmac
+@endDefstr
 
-@maindex \*R
-@Defmac{\\*R}
+@Defstr {*R}
 The `registered' sign.
-@end_Defmac
+@endDefstr
 
-@maindex \*(Tm
-@Defmac{\\*(Tm}
+@Defstr {Tm}
 The `trademark' sign.
-@end_Defmac
+@endDefstr
 
-@maindex \*(lq
-@maindex \*(rq
 @glindex lq
 @glindex rq
-@Defmac{\\*(lq}
-@Defmacx{\\*(rq}
-Left and right quote.
-This is equal to @code{\(lq} and @code{\(rq}, respectively.
-@end_Defmac
+@Defstr {lq}
+@Defstrx {rq}
+Left and right quote.  This is equal to @code{\(lq} and @code{\(rq},
+respectively.
+@endDefstr
+
+@c ---------------------------------------------------------------------
+
+@node Preprocessors in man pages,  , Predefined man strings, man
+@subsection Preprocessors in @file{man} pages
 
 @cindex preprocessor, calling convention
 @cindex calling convention of preprocessors
@@ -2211,14 +2386,15 @@ If a preprocessor like @code{gtbl} or @code{geqn} is needed, it has
 become common usage to make the first line of the man page look like
 this:
 
-@example
+@Example
 .\" @var{word}
-@end example
+@endExample
 
 @pindex geqn@r{, invocation in manual pages}
 @pindex grefer@r{, invocation in manual pages}
 @pindex gtbl@r{, invocation in manual pages}
 @pindex man@r{, invocation of preprocessors}
+@noindent
 Note the single space character after the double quote.  @var{word}
 consists of letters for the needed preprocessors: @samp{e} for
 @code{geqn}, @samp{r} for @code{grefer}, @samp{t} for @code{gtbl}.
@@ -2266,69 +2442,83 @@ and automatically call the right preprocessor(s).
 @c =====================================================================
 @c =====================================================================
 
-@node Programming Tutorial, Preprocessors, Macro Packages, Top
-@chapter Programming Tutorial
-@cindex programming tutorial
-@cindex tutorial for programming
+@node gtroff Reference, Preprocessors, Macro Packages, Top
+@chapter @code{gtroff} Reference
+@cindex reference, @code{gtroff}
+@cindex @code{gtroff} reference
 
 This chapter covers @strong{all} of the facilities of @code{gtroff}.
 Users of macro packages may skip it if not interested in details.
 
 
 @menu
-* Text::                        
-* Input Conventions::           
-* Measurements::                
-* Expressions::                 
-* Identifiers::                 
-* Embedded Commands::           
-* Registers::                   
-* Manipulating Filling and Adjusting::  
-* Manipulating Hyphenation::    
-* Manipulating Spacing::        
-* Tabs and Fields::             
-* Character Translations::      
-* Troff and Nroff Mode::        
-* Line Layout::                 
-* Page Layout::                 
-* Page Control::                
-* Fonts::                       
-* Sizes::                       
-* Strings::                     
-* Conditionals and Loops::      
-* Writing Macros::              
-* Page Motions::                
-* Drawing Requests::            
-* Traps::                       
-* Diversions::                  
-* Environments::                
-* I/O::                         
-* Postprocessor Access::        
-* Miscellaneous::               
-* Debugging::                   
-* Implementation Differences::  
-* Summary::                     
+* Text::
+* Input Conventions::
+* Measurements::
+* Expressions::
+* Identifiers::
+* Embedded Commands::
+* Registers::
+* Manipulating Filling and Adjusting::
+* Manipulating Hyphenation::
+* Manipulating Spacing::
+* Tabs and Fields::
+* Character Translations::
+* Troff and Nroff Mode::
+* Line Layout::
+* Page Layout::
+* Page Control::
+* Fonts::
+* Sizes::
+* Strings::
+* Conditionals and Loops::
+* Writing Macros::
+* Page Motions::
+* Drawing Requests::
+* Traps::
+* Diversions::
+* Environments::
+* Suppressing output::
+* I/O::
+* Postprocessor Access::
+* Miscellaneous::
+* Gtroff Internals::
+* Debugging::
+* Implementation Differences::
+* Summary::
 @end menu
 
 
 @c =====================================================================
 
-@node Text, Input Conventions, Programming Tutorial, Programming Tutorial
+@node Text, Input Conventions, gtroff Reference, gtroff Reference
 @section Text
 @cindex text, @code{gtroff} processing
 
 @code{gtroff} input files contain text with control commands
 interspersed throughout.  But, even without control codes, @code{gtroff}
-will still do several things with the input text: filling and adjusting,
-adding additional space after sentences, hyphenating and inserting
-implicit line breaks.
+still does several things with the input text:
+
+@itemize @bullet
+@item
+filling and adjusting
+
+@item
+adding additional space after sentences
+
+@item
+hyphenating
+
+@item
+inserting implicit line breaks
+@end itemize
 
 @menu
-* Filling and Adjusting::       
-* Hyphenation::                 
-* Sentences::                   
-* Tab Stops::                   
-* Implicit Line Breaks::        
+* Filling and Adjusting::
+* Hyphenation::
+* Sentences::
+* Tab Stops::
+* Implicit Line Breaks::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -2338,7 +2528,7 @@ implicit line breaks.
 @cindex filling
 @cindex adjusting
 
-When @code{gtroff} reads in text it collects words from input and fits
+When @code{gtroff} reads text, it collects words from the input and fits
 as many of them together on one output line as it can.  This is known as
 @dfn{filling}.
 
@@ -2346,11 +2536,11 @@ as many of them together on one output line as it can.  This is known as
 @cindex spaces, leading and trailing
 @cindex extra spaces
 @cindex trailing spaces
-Once @code{gtroff} has a @dfn{filled} line it will try to @dfn{adjust}
-it.  This means it will widen the spacing between words until the text
+Once @code{gtroff} has a @dfn{filled} line, it tries to @dfn{adjust}
+it.  This means it widens the spacing between words until the text
 reaches the right margin (in the default adjustment mode).  Extra spaces
 between words are preserved, but spaces at the end of lines are ignored.
-Spaces at the front of a line will cause a @dfn{break} (breaks will be
+Spaces at the front of a line cause a @dfn{break} (breaks are
 explained in @ref{Implicit Line Breaks})
 
 @xref{Manipulating Filling and Adjusting}.
@@ -2362,14 +2552,14 @@ explained in @ref{Implicit Line Breaks})
 @cindex hyphenation
 
 Since the odds are not great for finding a set of words, for every
-output line, which will fit nicely on a line without inserting excessive
-amounts of space between words, @code{gtroff} will hyphenate words so
-that lines can be justified without there being too much space between
+output line, which fit nicely on a line without inserting excessive
+amounts of space between words, @code{gtroff} hyphenates words so
+that it can justify lines without inserting too much space between
 words.  It uses an internal hyphenation algorithm (a simplified version
 of the algorithm used within @TeX{}) to indicate which words can be
-hyphenated and how to do so.  When a word is hyphenated the first part
-of the word will be added to the current filled line being output (with
-an attached hyphen), and the other portion will be added to the next
+hyphenated and how to do so.  When a word is hyphenated, the first part
+of the word is added to the current filled line being output (with
+an attached hyphen), and the other portion is added to the next
 line to be filled.
 
 @xref{Manipulating Hyphenation}.
@@ -2392,11 +2582,11 @@ a comma or a period as part of an abbreviation.
 @cindex space between sentences
 @cindex french-spacing
 @code{gtroff} does this by flagging certain characters (normally
-@samp{!}, @samp{?} and @samp{.}) as @dfn{end of sentence} characters.
+@samp{!}, @samp{?}, and @samp{.}) as @dfn{end of sentence} characters.
 When @code{gtroff} encounters one of these characters at the end of a
-line it will append two @dfn{sentence spaces} in the formatted output.
-(This justifies one of the conventions mentioned in @ref{Input
-Conventions}.)
+line, it appends a normal space followed by a @dfn{sentence space} in
+the formatted output.  (This justifies one of the conventions mentioned
+in @ref{Input Conventions}.)
 
 @cindex transparent characters
 @cindex character, transparent
@@ -2407,13 +2597,13 @@ Conventions}.)
 @cindex )
 @cindex ]
 @cindex *
-In addition, the following characters resp.@: glyphs are treated
+In addition, the following characters or glyphs are treated
 transparently while handling end of sentence characters: @samp{"},
 @samp{'}, @samp{)}, @samp{]}, @samp{*}, @code{dg}, and @code{rq}.
 
 See the @code{cflags} request in @ref{Using Symbols}, for more details.
 
-@findex \&
+@esindex \&
 To prevent the insertion of extra space after an end of sentence
 character (at the end of a line), append @code{\&}.
 
@@ -2428,15 +2618,15 @@ character (at the end of a line), append @code{\&}.
 
 @cindex @acronym{EBCDIC} encoding
 @code{gtroff} translates @dfn{tabulator characters}, also called
-@dfn{tabs} (normally code point @acronym{ASCII} @code{0x09} resp.@:
+@dfn{tabs} (normally code point @acronym{ASCII} @code{0x09} or
 @acronym{EBCDIC} @code{0x05}), in the input into movements to the next
 tabulator stop.  These tab stops are initially located every half inch
-across the page.  Using this, simple tables can easily be made.
+across the page.  Using this, simple tables can be made easily.
 However, it can often be deceptive as the appearance (and width) of the
 text on a terminal and the results from @code{gtroff} can vary greatly.
 
 Also, a possible sticking point is that lines beginning with tab
-characters will still be filled, again producing unexpected results.
+characters are still filled, again producing unexpected results.
 For example, the following input
 
 @multitable {12345678} {12345678} {12345678} {12345678}
@@ -2447,7 +2637,7 @@ For example, the following input
 @end multitable
 
 @noindent
-will produce
+produces
 
 @multitable {12345678} {12345678} {12345678} {12345678} {12345678} {12345678} {12345678}
 @item
@@ -2467,33 +2657,38 @@ will produce
 @cindex line break
 
 An important concept in @code{gtroff} is the @dfn{break}.  When a break
-occurs, @code{gtroff} will output the partially filled line
-(unjustified), and resume collecting and filling text on the next output
+occurs, @code{gtroff} outputs the partially filled line
+(unjustified), and resumes collecting and filling text on the next output
 line.
 
 @cindex blank line
 @cindex empty line
 @cindex line, blank
-There are several ways to cause a break in @code{gtroff}.  A blank line
-will not only cause a break, but it will also cause a one line vertical
-space (effectively a blank line) to be output.
+@cindex blank line macro
+@rqindex blm
+There are several ways to cause a break in @code{gtroff}.  A blank
+line not only causes a break, but it also outputs a one line vertical
+space (effectively a blank line).  Note that this behaviour can be
+modified with the blank line macro request @code{blm}.
+
+@c XXX xref for blm
 
 @cindex fill mode
 @cindex mode, fill
-A line which begins with a space will cause a break and the space will
-be output at the beginning of the next line.  Note that this space isn't
+A line that begins with a space causes a break and the space is
+output at the beginning of the next line.  Note that this space isn't
 adjusted, even in fill mode.
 
-The end of file will also cause a break -- otherwise the last line of
+The end of file also causes a break -- otherwise the last line of
 the document may vanish!
 
-Certain requests also cause breaks, implicitly or explicitly.  This will
-be discussed in @ref{Manipulating Filling and Adjusting}.
+Certain requests also cause breaks, implicitly or explicitly.  This is
+discussed in @ref{Manipulating Filling and Adjusting}.
 
 
 @c =====================================================================
 
-@node Input Conventions, Measurements, Text, Programming Tutorial
+@node Input Conventions, Measurements, Text, gtroff Reference
 @section Input Conventions
 @cindex input conventions
 @cindex conventions for input
@@ -2505,7 +2700,7 @@ paragraphs.  These are some conventions commonly used when typing
 
 @itemize @bullet
 @item
-Break lines after punctuation, particularly at the end of a sentence,
+Break lines after punctuation, particularly at the end of a sentence
 and in other logical places.  Keep separate phrases on lines by
 themselves, as entire phrases are often added or deleted when editing.
 
@@ -2515,13 +2710,13 @@ inserting more text.
 
 @item
 Do not try to do any formatting in a @acronym{WYSIWYG} manner (i.e.,
-don't try and use spaces to get proper indentation).
+don't try using spaces to get proper indentation).
 @end itemize
 
 
 @c =====================================================================
 
-@node Measurements, Expressions, Input Conventions, Programming Tutorial
+@node Measurements, Expressions, Input Conventions, gtroff Reference
 @section Measurements
 @cindex measurements
 
@@ -2531,7 +2726,7 @@ don't try and use spaces to get proper indentation).
 @cindex measurement units
 @cindex @code{u} unit
 @cindex unit, @code{u}
-@code{gtroff} (like any other programs) requires numeric parameters to
+@code{gtroff} (like many other programs) requires numeric parameters to
 specify various measurements.  Most numeric parameters@footnote{those
 that specify vertical or horizontal motion or a type size} may have a
 @dfn{measurement unit} attached.  These units are specified as a single
@@ -2540,9 +2735,9 @@ these units are understood, by @code{gtroff}, to be a multiple of its
 @dfn{basic unit}.  So, whenever a different measurement unit is
 specified @code{gtroff} converts this into its @dfn{basic units}.  This
 basic unit, represented by a @samp{u}, is a device dependent measurement
-which is quite small, ranging from 1/75th to 1/72000th of an inch.  The
-values may be given as fractional numbers; however, fractional basic
-units are always rounded to integers.
+which is quite small, ranging from 1/75@dmn{th} to 1/72000@dmn{th} of an
+inch.  The values may be given as fractional numbers; however,
+fractional basic units are always rounded to integers.
 
 Some of the measurement units are completely independent of any of the
 current settings (e.g.@: type size) of @code{gtroff}.
@@ -2553,7 +2748,8 @@ current settings (e.g.@: type size) of @code{gtroff}.
 @cindex @code{i} unit
 @cindex unit, @code{i}
 Inches.  An antiquated measurement unit still in use in certain
-backwards countries.  One inch is equal to@w{ }2.54@dmn{cm}.
+backwards countries with incredibly low-cost computer equipment.  One
+inch is equal to@w{ }2.54@dmn{cm}.
 
 @item c
 @cindex centimeter
@@ -2584,7 +2780,7 @@ Pica.  Another typesetting measurement.  6@w{ }Picas to an inch (and
 @xref{Fractional Type Sizes}, for a discussion of these units.
 @end table
 
-The other measurements understood by @code{gtroff} are dependent on
+The other measurements understood by @code{gtroff} depend on
 settings currently in effect in @code{gtroff}.  These are very useful
 for specifying measurements which should look proper with any size of
 text.
@@ -2619,7 +2815,7 @@ Vertical space.  This is equivalent to the current line spacing.
 @end table
 
 @menu
-* Default Units::               
+* Default Units::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -2634,34 +2830,35 @@ it can cause strange errors in some expressions.  For example, the line
 length request expects em units.  Here are several attempts to get a
 line length of 3.5@w{ }inches and their results:
 
-@example
+@Example
 3.5i      @result{}   3.5i
 7/2       @result{}   0i
 7/2i      @result{}   0i
 7i/2      @result{}   0.1i
 7i/2u     @result{}   3.5i
-@end example
+@endExample
 
 @noindent
-Everything will be converted to basic units first.  In the above example
-it is assumed that 1@dmn{i} equals@w{ }240@dmn{u}, and 1@dmn{m}
-equals@w{ }10@dmn{p} (thus 1@dmn{m} equals@w{ }33@dmn{u}).  The value
-7i/2 will be first handled as 7i/2m, then converted to 1680u/66u which
-is 25@dmn{u}, and this is approximately 0.1@dmn{i}.
+Everything is converted to basic units first.  In the above example it
+is assumed that 1@dmn{i} equals@w{ }240@dmn{u}, and 1@dmn{m} equals@w{
+}10@dmn{p} (thus 1@dmn{m} equals@w{ }33@dmn{u}).  The value 7@dmn{i}/2
+is first handled as 7@dmn{i}/2@dmn{m}, then converted to
+1680@dmn{u}/66@dmn{u} which is 25@dmn{u}, and this is approximately
+0.1@dmn{i}.
 
 @cindex measurements, specifying safely
-As a conclusion, the safest way to specify measurements is to always
+Thus, the safest way to specify measurements is to always
 attach a scaling indicator.  If you want to multiply or divide by a
 certain scalar value, use @samp{u} as the unit for that value.
 
 
 @c =====================================================================
 
-@node Expressions, Identifiers, Measurements, Programming Tutorial
+@node Expressions, Identifiers, Measurements, gtroff Reference
 @section Expressions
 @cindex expressions
 
-@code{gtroff} has most of operators common to other languages:
+@code{gtroff} has most arithmetic operators common to other languages:
 
 @c XXX more details; examples
 
@@ -2707,8 +2904,10 @@ Logical: @samp{&} (logical and), @samp{:} (logical or).
 @opindex -
 @opindex +
 @opindex !
-@findex if@r{, and the @samp{!} operator}
-@findex while@r{, and the @samp{!} operator}
+@rqindex if
+@rqindex while
+@cindex @code{if}, and the @samp{!} operator
+@cindex @code{while}, and the @samp{!} operator
 Unary operators: @samp{-} (negating, i.e.@: changing the sign), @samp{+}
 (just for completeness; does nothing in expressions), @samp{!} (logical
 not; this works only within @code{if} and @code{while} requests).  See
@@ -2740,7 +2939,7 @@ indicators in the evaluation of @var{e}.
 Parentheses may be used as in any other language.  However, in
 @code{gtroff} they are necessary to ensure order of evaluation.
 @code{gtroff} has no operator precedence; expressions are evaluated left
-to right.  This means that @samp{3+5*4} is evaluated as if it were
+to right.  This means that @code{gtroff} evaluates @samp{3+5*4} as if it were
 parenthesized like @samp{(3+5)*4}, not as @samp{3+(5*4)}, as might be
 expected.
 
@@ -2759,7 +2958,7 @@ input line.
 requests and escapes: @code{bp}, @code{in}, @code{ll}, @code{lt},
 @code{nm}, @code{nr}, @code{pl}, @code{pn}, @code{po}, @code{ps},
 @code{rt}, @code{ti}, @code{\R}, and @code{\s}.  Here the plus and minus
-signs indicate increments resp.@: decrements.
+signs indicate increments and decrements.
 
 @c XXX add more xref
 @xref{Setting Registers}.
@@ -2774,7 +2973,7 @@ expressions, unless the entire expression is surrounded by parentheses.
 
 @c =====================================================================
 
-@node Identifiers, Embedded Commands, Expressions, Programming Tutorial
+@node Identifiers, Embedded Commands, Expressions, gtroff Reference
 @section Identifiers
 @cindex identifiers
 
@@ -2788,13 +2987,13 @@ characters:
 @cindex whitespace characters
 @cindex newline character
 @cindex character, whitespace
-Whitespace characters (space, tabs, and newlines).
+Whitespace characters (spaces, tabs, and newlines).
 
 @item
 @cindex character, backspace
 @cindex backspace character
 @cindex @acronym{EBCDIC} encoding of backspace
-Backspace (@acronym{ASCII}@w{ }@code{0x08} resp.@: @acronym{EBCDIC}@w{
+Backspace (@acronym{ASCII}@w{ }@code{0x08} or @acronym{EBCDIC}@w{
 }@code{0x16}) and character code @code{0x01}.
 
 @item
@@ -2802,7 +3001,7 @@ Backspace (@acronym{ASCII}@w{ }@code{0x08} resp.@: @acronym{EBCDIC}@w{
 @cindex input characters, invalid
 @cindex characters, invalid input
 @cindex unicode
-The following input characters are invalid and will be ignored if
+The following input characters are invalid and are ignored if
 @code{groff} runs on a machine based on @acronym{ASCII}, causing a
 warning message of type @samp{input} (see @ref{Debugging}, for more
 details): @code{0x00}, @code{0x0B}, @code{0x0D}-@code{0x1F},
@@ -2815,46 +3014,46 @@ And here are the invalid input characters if @code{groff} runs on an
 
 Currently, some of these reserved codepoints are used internally, thus
 making it non-trivial to extend @code{gtroff} to cover Unicode or other
-character sets resp.@: encodings which use characters of these ranges.
+character sets and encodings which use characters of these ranges.
 
-Note that invalid characters will be removed before parsing; an
+Note that invalid characters are removed before parsing; an
 identifier @code{foo}, followed by an invalid character, followed by
-@code{bar} will be treated as @code{foobar}.
+@code{bar} is treated as @code{foobar}.
 @end itemize
 
 For example, any of the following is valid.
 
-@example
+@Example
 br
 PP
 (l
 end-list
 @@_
-@end example
+@endExample
 
-@findex ]
+@rqindex ]
+@noindent
 Note that identifiers longer than two characters with a closing bracket
 (@samp{]}) in its name can't be accessed with escape sequences which
-expect an identifier as a parameter.  For example, @samp{\[foo]]} will
-access the glyph @samp{foo}, followed by @samp{]}, whereas
+expect an identifier as a parameter.  For example, @samp{\[foo]]}
+accesses the glyph @samp{foo}, followed by @samp{]}, whereas
 @samp{\C'foo]'} really asks for glyph @samp{foo]}.
 
 @c XXX xref
 
-@Deffn{Escape, \\A, ident}
-Whether an identifier @var{ident} is valid in @code{gtroff} can be
-tested with the @code{\A} escape.  It expands to the character@w{ }1
-or@w{ }0 according to whether its argument (usually delimited by quotes)
-is or is not acceptable as the name of a string, macro, diversion,
-number register, environment, or font.  It will return@w{ }0 if no
-argument is given.  This is useful for looking up user input in some
-sort of associative table.
+@Defesc {\\A, ', ident, '}
+Test whether an identifier @var{ident} is valid in @code{gtroff}.  It
+expands to the character@w{ }1 or@w{ }0 according to whether its
+argument (usually delimited by quotes) is or is not acceptable as the
+name of a string, macro, diversion, number register, environment, or
+font.  It returns@w{ }0 if no argument is given.  This is useful for
+looking up user input in some sort of associative table.
 
-@example
+@Example
 \A'end-list'
     @result{} 1
-@end example
-@end_Deffn
+@endExample
+@endDefesc
 
 @xref{Escapes}, for details on parameter delimiting characters.
 
@@ -2864,9 +3063,9 @@ Identifiers in @code{gtroff} can be any length, but, in some contexts,
 @code{gtroff} needs to be told where identifiers end and text begins
 (and in different ways depending on their length):
 
-@findex (
-@findex [
-@findex ]
+@rqindex (
+@rqindex [
+@rqindex ]
 @itemize @bullet
 @item
 Single character.
@@ -2884,15 +3083,29 @@ in brackets.
 @cindex indentifiers, undefined
 Unlike many other programming languages, undefined identifiers are
 silently ignored or expanded to nothing.
+When @code{gtroff} finds an undefined identifier, it emits a
+warning then:
 
-@c XXX add info about -ww command line option.
+@itemize @bullet
+@item
+If the identifier is a string, macro, or diversion,
+@code{gtroff} defines it as empty.
+
+@item
+If the identifier is a number register, @code{gtroff}
+defines it with a value of@w{ }0.
+@end itemize
+
+@xref{Warnings}.
+
+@c XXX info about common identifier pool for strings and macros.
 
 @xref{Interpolating Registers}, and @ref{Strings}.
 
 
 @c =====================================================================
 
-@node Embedded Commands, Registers, Identifiers, Programming Tutorial
+@node Embedded Commands, Registers, Identifiers, gtroff Reference
 @section Embedded Commands
 @cindex embedded commands
 @cindex commands, embedded
@@ -2902,7 +3115,7 @@ implicit line breaking.  In order to gain further functionality,
 @code{gtroff} allows commands to be embedded into the text, in two ways.
 
 The first is a @dfn{request} which takes up an entire line, and does
-some large scale operation (e.g.@: break lines, start new pages).
+some large-scale operation (e.g.@: break lines, start new pages).
 
 The other is an @dfn{escape} which can be embedded anywhere in the text,
 or even as an argument to a request.
@@ -2911,9 +3124,9 @@ Escapes generally do more minor operations like sub- and superscripts,
 print a symbol, etc.
 
 @menu
-* Requests::                    
-* Macros::                      
-* Escapes::                     
+* Requests::
+* Macros::
+* Escapes::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -2927,30 +3140,74 @@ print a symbol, etc.
 @cindex no-break control character
 @cindex character, no-break control
 @cindex control character, no-break
-@findex '
-@findex .
+@rqindex '
+@rqindex .
 A request line begins with a control character, which is either a single
 quote (@samp{'}, the @dfn{no-break control character}) or a period
 (@samp{.}, the normal @dfn{control character}).  These can be changed;
 see @ref{Character Translations}, for details.  After this there may be
 optional tabs or spaces followed by an identifier which is the name of
 the request.  This may be followed by any number of space-separated
-arguments.
+arguments (@emph{no} tabs here).
+
+@cindex structuring source code of documents or macro packages
+@cindex documents, structuring the source code
+@cindex macro packages, strucuring the source code
+Since a control character followed by whitespace only is ignored, it
+is common practice to use this feature for structuring the source code
+of documents or macro packages.
+
+@Example
+.de foo
+.  tm This is foo.
+..
+.
+.
+.de bar
+.  tm This is bar.
+..
+@endExample
+
+@cindex blank line
+@cindex blank line macro
+@rqindex blm
+Another possibility is to use the blank line macro request @code{blm}
+by assigning an empty macro to it.
+
+@Example
+.de do-nothing
+..
+.blm do-nothing  \" activate blank line macro
+
+.de foo
+.  tm This is foo.
+..
+
+
+.de bar
+.  tm This is bar.
+..
+
+.blm             \" deactivate blank line macro
+@endExample
+
+@c XXX xref to blm
 
 @cindex zero width space character
 @cindex character, zero width space
 @cindex space character, zero width
-@findex \&@r{, escaping control characters}
+@esindex \&
+@cindex @code{\&}, escaping control characters
 To begin a line with a control character without it being interpreted,
 precede it with @code{\&}.  This represents a zero width space, which
-means it will not affect the output.
+means it does not affect the output.
 
 In most cases the period is used as a control character.  Several
-requests will cause a break implicitly; using the single quote control
-character will prevent this.
+requests cause a break implicitly; using the single quote control
+character prevents this.
 
 @menu
-* Request Arguments::           
+* Request Arguments::
 @end menu
 
 @node Request Arguments,  , Requests, Requests
@@ -2959,24 +3216,24 @@ character will prevent this.
 @cindex arguments to requests
 
 Arguments to requests (and macros) are processed much like the shell:
-The line is split into arguments according to spaces.  An argument which
-is intended to contain spaces can either be enclosed in quotes (single
-or double), or have the spaces @dfn{escaped} with backslashes.
+The line is split into arguments according to spaces.  An argument
+which is intended to contain spaces can either be enclosed in double
+quotes, or have the spaces @dfn{escaped} with backslashes.
 
 Here are a few examples:
 
-@example
+@Example
 .uh The Mouse Problem
 .uh "The Mouse Problem"
 .uh The\ Mouse\ Problem
-@end example
+@endExample
 
-@findex \~
-@findex \@key{SP}
+@esindex \~
+@esindex \@key{SP}
 @noindent
 The first line is the @code{uh} macro being called with 3 arguments,
 @samp{The}, @samp{Mouse}, and @samp{Problem}.  The latter two have the
-same effect or calling the @code{uh} macro with one argument, @samp{The
+same effect of calling the @code{uh} macro with one argument, @samp{The
 Mouse Problem}.@footnote{The last solution, i.e., using escaped spaces,
 is ``classical'' in the sense that it can be found in most @code{troff}
 documents.  Nevertheless, it is not optimal in all situations, since
@@ -2984,8 +3241,22 @@ documents.  Nevertheless, it is not optimal in all situations, since
 can't stretch.  @code{gtroff} provides a different command @code{\~} to
 insert a stretchable, non-breaking space.}
 
-@findex ds
-Note, however, that the @code{ds} request works differently.
+@cindex @code{"}, as a macro argument
+@cindex double quote, as a macro argument
+A double quote which isn't preceded by a space doesn't start a macro
+argument.  If not closing a string, it is printed literally.
+
+For example,
+
+@Example
+.xxx a" "b c" "de"fg"
+@endExample
+
+@noindent
+has the arguments @samp{a"}, @w{@samp{b c}}, @samp{de}, and @samp{fg"}.
+
+@rqindex ds
+Duoble quotes in the @code{ds} request are handled differently.
 @xref{Strings}, for more details.
 
 @c ---------------------------------------------------------------------
@@ -3011,9 +3282,9 @@ begin with a backslash and are followed by a single character which
 indicates the function to be performed.  The escape character can be
 changed; see @ref{Character Translations}.
 
-@findex (
-@findex [
-@findex ]
+@rqindex (
+@rqindex [
+@rqindex ]
 Escape sequences which require an identifier as a parameter accept three
 possible syntax forms.
 
@@ -3034,13 +3305,13 @@ until a closing bracket as the identifier.
 @noindent
 Examples:
 
-@example
+@Example
 \fB
 \n(XX
 \*[TeX]
-@end example
+@endExample
 
-@findex '
+@rqindex '
 @cindex argument delimiting characters
 @cindex characters, argument delimiting
 @cindex delimiting characters for arguments
@@ -3050,19 +3321,19 @@ In such cases the argument is traditionally enclosed in single quotes
 sequences).  The enclosed text is then processed according to what that
 escape expects.  Example:
 
-@example
+@Example
 \l'1.5i\(bu'
-@end example
+@endExample
 
-@findex \o
-@findex \b
-@findex \X
+@esindex \o
+@esindex \b
+@esindex \X
 Note that the quote character can be replaced with any other character
 which does not occur in the argument (even a newline or a space
 character) in the following escapes: @code{\o}, @code{\b}, and
 @code{\X}.  This makes e.g.
 
-@example
+@Example
 A caf
 \o
 e\'
@@ -3070,39 +3341,39 @@ e\'
 
 in Paris
   @result{} A caf@'e in Paris
-@end example
+@endExample
 
 @noindent
 possible, but it is better not to use this feature to avoid confusion.
 
-@findex \%
-@findex \@key{SP}
-@findex \|
-@findex \^
-@findex \@{
-@findex \@}
-@findex \'
-@findex \`
-@findex \-
-@findex \_
-@findex \!
-@findex \?
-@findex \@@
-@findex \)
-@findex \/
-@findex \,
-@findex \&
-@findex \~
-@findex \0
-@findex \a
-@findex \c
-@findex \d
-@findex \e
-@findex \E
-@findex \p
-@findex \r
-@findex \t
-@findex \u
+@esindex \%
+@esindex \@key{SP}
+@esindex \|
+@esindex \^
+@esindex \@{
+@esindex \@}
+@esindex \'
+@esindex \`
+@esindex \-
+@esindex \_
+@esindex \!
+@esindex \?
+@esindex \@@
+@esindex \)
+@esindex \/
+@esindex \,
+@esindex \&
+@esindex \~
+@esindex \0
+@esindex \a
+@esindex \c
+@esindex \d
+@esindex \e
+@esindex \E
+@esindex \p
+@esindex \r
+@esindex \t
+@esindex \u
 The following escapes sequences (which are handled similarly to
 characters since they don't take a parameter) are also allowed as
 delimiters: @code{\%}, @w{@samp{\ }}, @code{\|}, @code{\^}, @code{\@{},
@@ -3112,24 +3383,24 @@ delimiters: @code{\%}, @w{@samp{\ }}, @code{\|}, @code{\^}, @code{\@{},
 @code{\E}, @code{\p}, @code{\r}, @code{\t}, and @code{\u}.  Again, don't
 use these if possible.
 
-@findex \A
-@findex \Z
-@findex \C
-@findex \w
+@esindex \A
+@esindex \Z
+@esindex \C
+@esindex \w
 No newline characters as delimiters are allowed in the following
 escapes: @code{\A}, @code{\Z}, @code{\C}, and @code{\w}.
 
-@findex \D
-@findex \h
-@findex \H
-@findex \l
-@findex \L
-@findex \N
-@findex \R
-@findex \s
-@findex \S
-@findex \v
-@findex \x
+@esindex \D
+@esindex \h
+@esindex \H
+@esindex \l
+@esindex \L
+@esindex \N
+@esindex \R
+@esindex \s
+@esindex \S
+@esindex \v
+@esindex \x
 Finally, the escapes @code{\D}, @code{\h}, @code{\H}, @code{\l},
 @code{\L}, @code{\N}, @code{\R}, @code{\s}, @code{\S}, @code{\v}, and
 @code{\x} can't use the following characters as delimiters:
@@ -3167,28 +3438,28 @@ The (single-character) operators @samp{+-/*%<>=&:().}.
 The space, tab, and newline characters.
 
 @item
-@findex \%
-@findex \@{
-@findex \@}
-@findex \'
-@findex \`
-@findex \-
-@findex \_
-@findex \!
-@findex \@@
-@findex \/
-@findex \c
-@findex \e
-@findex \p
+@esindex \%
+@esindex \@{
+@esindex \@}
+@esindex \'
+@esindex \`
+@esindex \-
+@esindex \_
+@esindex \!
+@esindex \@@
+@esindex \/
+@esindex \c
+@esindex \e
+@esindex \p
 All escape sequences except @code{\%}, @code{\@{}, @code{\@}},
 @code{\'}, @code{\`}, @code{\-}, @code{\_}, @code{\!}, @code{\@@},
 @code{\/}, @code{\c}, @code{\e}, and @code{\p}.
 @end itemize
 
-@findex \\
-@findex \e
-@findex \E
-To have a backslash (resp.@: the current escape character) appear in the
+@esindex \\
+@esindex \e
+@esindex \E
+To have a backslash (actually, the current escape character) appear in the
 output several escapes are defined: @code{\\}, @code{\e} or @code{\E}.
 These are very similar, and only differ with respect to being used in
 macros or diversions.  @xref{Copy-in Mode}, and @ref{Diversions}, for
@@ -3199,7 +3470,7 @@ more information.
 @xref{Identifiers}, and @ref{Character Translations}.
 
 @menu
-* Comments::                    
+* Comments::
 @end menu
 
 @node Comments,  , Escapes, Escapes
@@ -3210,17 +3481,18 @@ Probably one of the most@footnote{Unfortunately, this is a lie.  But
 hopefully future @code{gtroff} hackers will believe it @code{:-)}}
 common forms of escapes is the comment.
 
-@Deffn{Escape, \\"}
+@Defesc {\\", , , }
 Start a comment.  Everything to the end of the input line is ignored.
 
 This may sound simple, but it can be tricky to keep the comments from
 interfering with the appearance of the final output.
 
-@findex ds
-If the escape is to the right of some text or a request, that portion of
-the line will be ignored, but the space leading up to it will be noticed
-by @code{gtroff}.  This only affects the @code{.ds} request.
-@c XXX (any others?)
+@rqindex ds
+@rqindex as
+If the escape is to the right of some text or a request, that portion
+of the line is ignored, but the space leading up to it is noticed by
+@code{gtroff}.  This only affects the @code{.ds} and @code{.as}
+request.
 
 @cindex tabs before comments
 @cindex comments, lining up with tabs
@@ -3230,69 +3502,95 @@ request and macro arguments.
 
 @cindex undefined request
 @cindex request, undefined
-A comment on a line by itself will be treated as a blank line, because
+A comment on a line by itself is treated as a blank line, because
 after eliminating the comment, that is all that remains:
 
-@example
+@Example
 Test
 \" comment
 Test
-@end example
+@endExample
 
 @noindent
-will produce
+produces
 
-@example
+@Example
 Test
 
 Test
-@end example
+@endExample
 
-As a consequence, it is common to start the line with @code{.\"} which
-will cause the line to be treated as an undefined request and thus
-ignored completely.
+To avoid this, it is common to start the line with @code{.\"} which
+causes the line to be treated as an undefined request and thus ignored
+completely.
 
-@findex '
+@rqindex '
 Another commenting scheme seen sometimes is three consecutive single
 quotes (@code{'''}) at the beginning of a line.  This works, but
-@code{gtroff} will give a warning about an undefined macro (namely
+@code{gtroff} gives a warning about an undefined macro (namely
 @code{''}), which is harmless, but irritating.
-@end_Deffn
+@endDefesc
 
-@Deffn{Escape, \\#}
-To avoid all this, @code{gtroff} has a new comment mechanism using
-the @code{\#} escape.  This escape works the same as @code{\"} except
-that the newline is also ignored:
+@Defesc {\\#, , , }
+To avoid all this, @code{gtroff} has a new comment mechanism using the
+@code{\#} escape.  This escape works the same as @code{\"} except that
+the newline is also ignored:
 
-@example
+@Example
 Test
 \# comment
 Test
-@end example
+@endExample
 
 @noindent
-will produce
+produces
 
-@example
+@Example
 Test Test
-@end example
+@endExample
 
 @noindent
 as expected.
-@end_Deffn
+@endDefesc
+
+@Defreq {ig, yy}
+Ignore all input until @code{gtroff} encounters the macro named
+@code{.}@var{yy} on a line by itself (or @code{..} if @var{yy} is not
+specified).  This is useful for commenting out large blocks of text:
+
+@Example
+text text text...
+.ig
+This is part of a large block
+of text that has been
+temporarily(?) commented out.
+
+We can restore it simply by removing
+the .ig request and the ".." at the
+end of the block.
+..
+More text text text...
+@endExample
+
+@noindent
+produces
 
-@findex ig
-For commenting away large blocks of text, the @code{ig} request may be
-useful.
+@Example
+text text text@dots{}  More text text text@dots{}
+@endExample
 
-@c XXX definition of .ig
+@noindent
+Note that the commented-out block of text does not
+cause a break.
 
-@xref{Strings}.
+The input is read in copy-mode; auto-incremented registers @emph{are}
+affected (@pxref{Auto-increment}).
+@endDefreq
 
 
 @c =====================================================================
 
-@node Registers, Manipulating Filling and Adjusting, Embedded Commands, Programming Tutorial
+@node Registers, Manipulating Filling and Adjusting, Embedded Commands, gtroff Reference
 @section Registers
 @cindex registers
 
@@ -3303,11 +3601,11 @@ details of formatting parameters.
 @xref{Identifiers}, for details on register identifiers.
 
 @menu
-* Setting Registers::           
-* Interpolating Registers::     
-* Auto-increment::              
-* Assigning Formats::           
-* Built-in Registers::          
+* Setting Registers::
+* Interpolating Registers::
+* Auto-increment::
+* Assigning Formats::
+* Built-in Registers::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -3317,46 +3615,46 @@ details of formatting parameters.
 @cindex setting registers
 @cindex registers, setting
 
-Registers are defined resp.@: set via the @code{nr} request or the
+Define or set registers using the @code{nr} request or the
 @code{\R} escape.
 
-@Deffn{Request, nr, ident value}
-@Deffnx{Escape, \\R, ident value}
-Set number register @var{ident} to @var{value}.  If @var{ident} doesn't
-exist, it will be created.
+@Defreq {nr, ident value}
+@Defescx {\\R, ', ident value, '}
+Set number register @var{ident} to @var{value}.  If @var{ident}
+doesn't exist, @code{gtroff} creates it.
 
-The argument to @code{\R} has to be enclosed in quotes usually.
+The argument to @code{\R} usually has to be enclosed in quotes.
 @xref{Escapes}, for details on parameter delimiting characters.
-@end_Deffn
+@endDefreq
 
 For example, the following two lines are equivalent:
 
-@example
+@Example
 .nr a 1
 \R'a 1'
-@end example
+@endExample
 
 Both @code{nr} and @code{\R} have two additional special forms to
-increment resp.@: decrement a register.
+increment or decrement a register.
 
-@Deffn{Request, nr, ident +value}
-@Deffnx{Request, nr, ident -value}
-@Deffnx{Escape, \\R, ident +value}
-@Deffnx{Escape, \\R, ident -value}
+@Defreq {nr, ident @t{+}@Var{value}}
+@Defreqx {nr, ident @t{-}@Var{value}}
+@Defescx {\\R, ', ident @t{+}@Var{value}, '}
+@Defescx {\\R, ', ident @t{-}@Var{value}, '}
 Increment (decrement) register @var{ident} by @var{value}.
 
-@example
+@Example
 .nr a 1
 .nr a +1
 \na
     @result{} 2
-@end example
+@endExample
 
 @cindex negating register values
 To assign the negated value of a register to another register, some care
 must be taken to get the desired result:
 
-@example
+@Example
 .nr a 7
 .nr b 3
 .nr a -\nb
@@ -3365,14 +3663,14 @@ must be taken to get the desired result:
 .nr a (-\nb)
 \na
     @result{} -3
-@end example
+@endExample
 
 @noindent
 The surrounding parentheses prevent the interpretation of the minus sign
 as a decrementing operator.  An alternative is to start the assignment
 with a @samp{0}:
 
-@example
+@Example
 .nr a 7
 .nr b -3
 .nr a \nb
@@ -3381,26 +3679,25 @@ with a @samp{0}:
 .nr a 0\nb
 \na
     @result{} -3
-@end example
-@end_Deffn
+@endExample
+@endDefreq
 
-@Deffn{Request, rr, ident}
+@Defreq {rr, ident}
 Remove number register @var{ident}.  If @var{ident} doesn't exist, the
 request is ignored.
-@end_Deffn
+@endDefreq
 
-@Deffn{Request, rnn, ident1 ident2}
+@Defreq {rnn, ident1 ident2}
 Rename number register @var{ident1} to @var{ident2}.  If either
 @var{ident1} or @var{ident2} doesn't exist, the request is ignored.
-@end_Deffn
+@endDefreq
 
-@Deffn{Request, aln, ident1 ident2}
-This request creates an alias @var{ident1} for a number register
-@var{ident2}.  The new name and the old name will be exactly equivalent.
-If @var{ident1} is undefined, a warning of type @samp{reg} will be
-generated, and the request will be ignored.  @xref{Debugging}, for
-information about warnings.
-@end_Deffn
+@Defreq {aln, ident1 ident2}
+Create an alias @var{ident1} for a number register @var{ident2}.  The
+new name and the old name are exactly equivalent.  If @var{ident1} is
+undefined, a warning of type @samp{reg} is generated, and the request
+is ignored.  @xref{Debugging}, for information about warnings.
+@endDefreq
 
 @c ---------------------------------------------------------------------
 
@@ -3411,19 +3708,37 @@ information about warnings.
 
 Numeric registers can be accessed via the @code{\n} escape.
 
-@Deffn{Escape, \\n, ident}
-@c XXX is the following correct?
-Interpolate number register @var{ident}.  This means that the value of
+@cindex nested assignments
+@cindex assignments, nested
+@cindex indirect assignments
+@cindex assignments, indirect
+@Defesc {\\n, , i, }
+@Defescx {\\n, @lparen{}, id, }
+@Defescx {\\n, @lbrack{}, ident, @rbrack}
+Interpolate number register with name @var{ident} (one-character name
+@var{i}, two-character name @var{id}).  This means that the value of
 the register is expanded in-place while @code{gtroff} is parsing the
-input line.
+input line.  Nested assignments (also called indirect assignments) are
+possible.
 
-@example
+@Example
 .nr a 5
 .nr as \na+\na
 \n(as
     @result{} 10
-@end example
-@end_Deffn
+@endExample
+
+@Example
+.nr a1 5
+.nr ab 6
+.ds str b
+.ds num 1
+\n[a\n[num]]
+    @result{} 5
+\n[a\*[str]]
+    @result{} 6
+@endExample
+@endDefesc
 
 @c ---------------------------------------------------------------------
 
@@ -3432,31 +3747,40 @@ input line.
 @cindex auto-increment
 @cindex increment, automatic
 
-Number registers can also be auto-incremented and auto-decremented.  The
-increment resp.@: decrement factor can be specified with a third
+Number registers can also be auto-incremented and auto-decremented.
+The increment or decrement value can be specified with a third
 argument to the @code{nr} request or @code{\R} escape.
 
-@findex \R
-@Deffn{Request, nr, ident value incr}
+@esindex \R
+@Defreq {nr, ident value incr}
 Set number register @var{ident} to @var{value}; the increment for
-auto-incrementing is set to @var{incr}.  Note that the @code{\R} escape
-doesn't support this notation.
-@end_Deffn
-
-To activate auto-incrementing, the escape @code{\n} has a special syntax
-form.
-
-@Deffn{Escape, \\n, +ident}
-@Deffnx{Escape, \\n, -ident}
-Before interpolating, increment resp.@: decrement @var{ident} by the
+auto-incrementing is set to @var{incr}.  Note that the @code{\R}
+escape doesn't support this notation.
+@endDefreq
+
+To activate auto-incrementing, the escape @code{\n} has a special
+syntax form.
+
+@Defesc {\\n, +, i, }
+@Defescx {\\n, -, i, }
+@Defescx {\\n, @lparen{}+, id, }
+@Defescx {\\n, @lparen{}-, id, }
+@Defescx {\\n, +@lparen{}, id, }
+@Defescx {\\n, -@lparen{}, id, }
+@Defescx {\\n, @lbrack{}+, ident, @rbrack{}}
+@Defescx {\\n, @lbrack{}-, ident, @rbrack{}}
+@Defescx {\\n, +@lbrack{}, ident, @rbrack{}}
+@Defescx {\\n, -@lbrack{}, ident, @rbrack{}}
+Before interpolating, increment or decrement @var{ident}
+(one-character name @var{i}, two-character name @var{id}) by the
 auto-increment value as specified with the @code{nr} request (or the
-@code{\R} escape).  If no auto-increment value has been specified, both
-syntax forms are identical to @code{\n}.
-@end_Deffn
+@code{\R} escape).  If no auto-increment value has been specified,
+these syntax forms are identical to @code{\n}.
+@endDefesc
 
 For example,
 
-@example
+@Example
 .nr a 0 1
 .nr xx 0 5
 .nr foo 0 -2
@@ -3465,24 +3789,24 @@ For example,
 \n-(xx, \n-(xx, \n-(xx, \n-(xx, \n-(xx
 .br
 \n+[foo], \n+[foo], \n+[foo], \n+[foo], \n+[foo]
-@end example
+@endExample
 
 @noindent
 produces
 
-@example
+@Example
 1, 2, 3, 4, 5
 -5, -10, -15, -20, -25
 -2, -4, -6, -8, -10
-@end example
+@endExample
 
 @cindex increment value without changing the register
-To change the increment value without changing the value of a register,
-the following can be used:
+To change the increment value without changing the value of a register
+(@var{a} in the example), the following can be used:
 
-@example
+@Example
 .nr a \na 10
-@end example
+@endExample
 
 @c ---------------------------------------------------------------------
 
@@ -3491,21 +3815,21 @@ the following can be used:
 @cindex assigning formats
 @cindex formats, assigning
 
-When a register is used in the text of an input file (as opposed to part
-of an expression), it is textually replaced (or interpolated) with a
-representation of that number.  This output format can be changed to a
-variety of formats (numbers, Roman numerals, etc.).  This is done using
-the @code{af} request.
+When a register is used in the text of an input file (as opposed to
+part of an expression), it is textually replaced (or interpolated)
+with a representation of that number.  This output format can be
+changed to a variety of formats (numbers, Roman numerals, etc.).  This
+is done using the @code{af} request.
 
-@Deffn{Request, af, ident format}
+@Defreq {af, ident format}
 Change the output format of a number register.  The first argument
 @var{ident} is the name of the number register to be changed, and the
-second argument @var{format} is the output format.  The following output
-formats are available:
+second argument @var{format} is the output format.  The following
+output formats are available:
 
 @table @code
 @item 1
-Decimal arabic numbers.  This is the default format: 1, 2, 3,@w{
+Decimal arabic numbers.  This is the default format: 0, 1, 2, 3,@w{
 }@enddots{}
 
 @item 0@dots{}0
@@ -3518,7 +3842,7 @@ format @samp{1} could be specified as @samp{0} also (and exactly this is
 returned by the @code{\g} escape, see below).
 
 @item I
-@cindex roman numerals
+@cindex Roman numerals
 @cindex numerals, Roman
 Upper-case Roman numerals: 0, I, II, III, IV,@w{ }@enddots{}
 
@@ -3526,19 +3850,19 @@ Upper-case Roman numerals: 0, I, II, III, IV,@w{ }@enddots{}
 Lower-case Roman numerals: 0, i, ii, iii, iv,@w{ }@enddots{}
 
 @item A
-Upper-case letters: A, B, C, @dots{},@w{ }Z, AA, AB,@w{ }@enddots{}
+Upper-case letters: 0, A, B, C, @dots{},@w{ }Z, AA, AB,@w{ }@enddots{}
 
 @item a
-Lower-case letters: a, b, c, @dots{},@w{ }z, aa, ab,@w{ }@enddots{}
+Lower-case letters: 0, a, b, c, @dots{},@w{ }z, aa, ab,@w{ }@enddots{}
 @end table
 
-Omitting the number register format will cause a warning of type
+Omitting the number register format causes a warning of type
 @samp{missing}.  @xref{Debugging}, for more details.  Specifying a
 nonexistent format causes an error.
 
-The following example will produce @samp{10, X, j, 010}:
+The following example produces @samp{10, X, j, 010}:
 
-@example
+@Example
 .nr a 10
 .af a 1           \" the default format
 \na,
@@ -3548,35 +3872,38 @@ The following example will produce @samp{10, X, j, 010}:
 \na,
 .af a 001
 \na
-@end example
+@endExample
 
-@cindex roman numerals, maximum and minimum
+@cindex Roman numerals, maximum and minimum
 @cindex maximum values of Roman numerals
 @cindex minimum values of Roman numerals
 The largest number representable for the @samp{i} and @samp{I} formats
-is 39999 (resp.@: -39999); @acronym{UNIX} @code{troff} uses @samp{z} and
-@samp{w} to represent 10000 and 5000 in Roman numerals, and so does
+is 39999 (or @minus{}39999); @acronym{UNIX} @code{troff} uses @samp{z}
+and @samp{w} to represent 10000 and 5000 in Roman numerals, and so does
 @code{gtroff}.  Currently, the correct glyphs of Roman numeral five
 thousand and Roman numeral ten thousand (Unicode code points
 @code{U+2182} and @code{U+2181}, respectively) are not available.
 
-If @var{ident} doesn't exist, it will be created.
+If @var{ident} doesn't exist, it is created.
 
 @cindex read-only register, changing format
 @cindex changing format, read-only register
 Changing the output format of a read-only register causes an error.  It
 is necessary to first copy the register's value to a writeable register,
 then apply the @code{af} request to this other register.
-@end_Deffn
+@endDefreq
 
 @cindex format of register
 @cindex register, format
-@Deffn{Escape, \\g, ident}
-Return the current format of the specified register @var{ident}.  For
-example, @samp{\ga} after the previous example would produce the string
-@samp{000}.  If the register hasn't been defined yet, nothing is
-returned.
-@end_Deffn
+@Defesc {\\g, , i, }
+@Defescx {\\g, @lparen{}, id, }
+@Defescx {\\g, @lbrack{}, ident, @rbrack{}}
+Return the current format of the specified register @var{ident}
+(one-character name @var{i}, two-character name @var{id}).  For
+example, @samp{\ga} after the previous example would produce the
+string @samp{000}.  If the register hasn't been defined yet, nothing
+is returned.
+@endDefesc
 
 @c ---------------------------------------------------------------------
 
@@ -3635,25 +3962,25 @@ incorrectly claimed that @code{yr} contains the last two digits of the
 year.  That claim has never been true of either traditional @code{troff}
 or GNU @code{troff}.  Old @code{troff} input that looks like this:
 
-@example
+@Example
 '\" The following line stopped working after 1999
 This document was formatted in 19\n(yr.
-@end example
+@endExample
 
 @noindent
 can be corrected as follows:
 
-@example
+@Example
 This document was formatted in \n[year].
-@end example
+@endExample
 
 @noindent
 or, to be portable to older @code{troff} versions, as follows:
 
-@example
+@Example
 .nr y4 1900+\n(yr
 This document was formatted in \n(y4.
-@end example
+@endExample
 
 @item .c
 @vindex .c
@@ -3667,27 +3994,27 @@ affecting both @samp{.c} and @samp{c.}.
 
 @item ln
 @vindex ln
-@findex nm
+@rqindex nm
 @cindex output line number register
 @cindex line number, output, register
 The current @emph{output} line number after a call to the @code{nm}
 request to activate line numbering.
 
-@c XXX xref nm request
+@xref{Miscellaneous}, for more information about line numbering.
 
 @item .x
 @vindex .x
 @cindex major version number register
 @cindex version number, major, register
 The major version number.  For example, if the version number is@w{
-}1.03 then @code{.x} will contain@w{ }@samp{1}.
+}1.03 then @code{.x} contains@w{ }@samp{1}.
 
 @item .y
 @vindex .y
 @cindex minor version number register
 @cindex version number, minor, register
 The minor version number.  For example, if the version number is@w{
-}1.03 then @code{.y} will contain@w{ }@samp{03}.
+}1.03 then @code{.y} contains@w{ }@samp{03}.
 
 @item .Y
 @vindex .Y
@@ -3721,9 +4048,9 @@ If @code{gtroff} is called with the @option{-T} command line option, the
 number register @code{.T} is set to@w{ }1, and zero otherwise.
 @xref{Groff Options}.
 
-@maindex \*(.T
+@stindex .T
 @cindex output device register
-Additionally, @code{gtroff} predefines a single (read/write) string
+Additionally, @code{gtroff} predefines a single read-write string
 register @code{.T} which contains the current output device (for
 example, @samp{latin1} or @samp{ps}).
 @end table
@@ -3731,7 +4058,7 @@ example, @samp{latin1} or @samp{ps}).
 
 @c =====================================================================
 
-@node Manipulating Filling and Adjusting, Manipulating Hyphenation, Registers, Programming Tutorial
+@node Manipulating Filling and Adjusting, Manipulating Hyphenation, Registers, gtroff Reference
 @section Manipulating Filling and Adjusting
 @cindex manipulating filling and adjusting
 @cindex filling and adjusting, manipulating
@@ -3741,70 +4068,72 @@ example, @samp{latin1} or @samp{ps}).
 
 @cindex break
 @cindex line break
-@findex bp
-@findex ce
-@findex cf
-@findex fi
-@findex fl
-@findex in
-@findex nf
-@findex rj
-@findex sp
-@findex ti
-@findex trf
+@rqindex bp
+@rqindex ce
+@rqindex cf
+@rqindex fi
+@rqindex fl
+@rqindex in
+@rqindex nf
+@rqindex rj
+@rqindex sp
+@rqindex ti
+@rqindex trf
 Various ways of causing @dfn{breaks} were given in @ref{Implicit Line
-Breaks}.  The @code{br} request will likewise cause a break.  Several
-other requests will also cause breaks, but implicitly.  These are
+Breaks}.  The @code{br} request likewise causes a break.  Several
+other requests also cause breaks, but implicitly.  These are
 @code{bp}, @code{ce}, @code{cf}, @code{fi}, @code{fl}, @code{in},
 @code{nf}, @code{rj}, @code{sp}, @code{ti}, and @code{trf}.
 
-@Deffn{Request, br, }
-Break the current line, i.e., the input collected so far will be emitted
+@Defreq {br, }
+Break the current line, i.e., the input collected so far is emitted
 without adjustment.
 
-If the no-break control character is used, no break will happen:
+If the no-break control character is used, @code{gtroff} suppresses
+the break:
 
-@example
+@Example
 a
 'br
 b
     @result{} a b
-@end example
-@end_Deffn
+@endExample
+@endDefreq
 
-Initially, @code{gtroff} will fill and adjust text to both margins.
+Initially, @code{gtroff} fills and adjusts text to both margins.
 Filling can be disabled via the @code{nf} request and re-enabled with
 the @code{fi} request.
 
 @cindex fill mode
 @cindex mode, fill
-@vindex .u
-@Deffn{Request, fi, }
+@Defreq {fi, }
+@Defregx {.u}
 Activate fill mode (which is the default).  This request implicitly
-enables adjusting; it will also cause a break in the text currently
-being filled.  The number register @code{.u} is set to@w{ }1.
+enables adjusting; it also inserts a break in the text currently being
+filled.  The read-only number register @code{.u} is set to@w{ }1.
 
 The fill mode status is associated with the current environment
 (@pxref{Environments}).
-@end_Deffn
+@endDefreq
 
 @cindex no-fill mode
 @cindex mode, no-fill
-@Deffn{Request, nf, }
+@Defreq {nf, }
 Activate no-fill mode.  Input lines are output as-is, retaining line
-breaks.  The current line length will be ignored.  This command
-implicitly disables adjusting; it also causes a break.  The number
-register @code{.u} will be set to@w{ }0.
+breaks and ignoring the current line length.  This command implicitly
+disables adjusting; it also causes a break.  The number register
+@code{.u} is set to@w{ }0.
 
 The fill mode status is associated with the current environment
 (@pxref{Environments}).
-@end_Deffn
+@endDefreq
 
-@Deffn{Request, ad, [@var{mode}]}
+@Defreq {ad, [@Var{mode}]}
+@Defregx {.j}
 Set adjusting mode.
 
-Activation and deactivation of adjusting will be implicitly done with
-calls to the @code{fi} resp.@: @code{nf} requests.
+Activation and deactivation of adjusting is done implicitly with
+calls to the @code{fi} or @code{nf} requests.
 
 @var{mode} can have one of the following values:
 
@@ -3820,7 +4149,7 @@ Adjust text to the right margin, producing ragged-left text.
 
 @item c
 @cindex centered text
-@findex ce
+@rqindex ce
 Center filled text.  This is different to the @code{ce} request which
 only centers text without filling.
 
@@ -3829,11 +4158,11 @@ only centers text without filling.
 Justify to both margins.  This is the default used by @code{gtroff}.
 @end table
 
-With no argument, @code{gtroff} will adjust lines in the same way it did
-before adjusting has been deactivated (with a call to @code{na}, for
+With no argument, @code{gtroff} adjusts lines in the same way it did
+before adjusting was deactivated (with a call to @code{na}, for
 example).
 
-@example
+@Example
 text
 .ad r
 text
@@ -3843,48 +4172,49 @@ text
 text
 .ad  \" back to centering
 text
-@end example
+@endExample
 
-@vindex .j
 @cindex current adjustment mode register
-The current adjustment mode is available in the number register
-@code{.j}; it can be stored and subsequently used to set adjustment.
+The current adjustment mode is available in the read-only number
+register @code{.j}; it can be stored and subsequently used to set
+adjustment.
 
 The adjustment mode status is associated with the current environment
 (@pxref{Environments}).
-@end_Deffn
+@endDefreq
 
-@Deffn{Request, na, }
+@Defreq {na, }
 Disable adjusting.  This request won't change the current adjustment
-mode: A call to @code{ad} afterwards will use the previous adjustment
+mode: A subsequent call to @code{ad} uses the previous adjustment
 setting.
 
 The adjustment mode status is associated with the current environment
 (@pxref{Environments}).
-@end_Deffn
+@endDefreq
 
-@Deffn{Escape, \\p, }
+@Defesc {\\p, , , }
 Adjust the current line and cause a break.
 
-In most cases this will produce very ugly results, since @code{gtroff}
+In most cases this produces very ugly results, since @code{gtroff}
 doesn't have a sophisticated paragraph building algorithm (as @TeX{}
-does, for example); instead, @code{gtroff} fills and adjusts a paragraph
+have, for example); instead, @code{gtroff} fills and adjusts a paragraph
 line by line:
 
-@example
+@Example
   This is an uninteresting sentence.
   This is an uninteresting sentence.\p
   This is an uninteresting sentence.
-@end example
+@endExample
 
+@noindent
 is formatted as
 
-@example
+@Example
   This is  an uninteresting  sentence.   This  is an
   uninteresting                            sentence.
   This is an uninteresting sentence.
-@end example
-@end_Deffn
+@endExample
+@endDefesc
 
 @cindex word space size
 @cindex size of word space
@@ -3892,100 +4222,125 @@ is formatted as
 @cindex sentence space size
 @cindex size of sentence space
 @cindex space between sentences
-@Deffn{Request, ss, word_space_size [@var{sentence_space_size}]}
+@Defreq {ss, word_space_size [@Var{sentence_space_size}]}
+@Defregx {.ss}
+@Defregx {.sss}
 Change the minimum size of a space between filled words.  It takes its
-units as one twelfth of the space width parameter for the current font.
-Initially both the @var{word_space_size} and @var{sentence_space_size}
-are@w{ }12.
+units as one twelfth of the space width parameter for the current
+font.  Initially both the @var{word_space_size} and
+@var{sentence_space_size} are@w{ }12.
 
 @cindex fill mode
 @cindex mode, fill
-If two arguments are given to the @code{ss} request, the second argument
-sets the sentence space size.  If the second argument is not given,
-sentence space size will be set to @var{word_space_size}.  The sentence
-space size is used in two circumstances: if the end of a sentence occurs
-at the end of a line in fill mode, then both an inter-word space and a
-sentence space will be added; if two spaces follow the end of a sentence
-in the middle of a line, then the second space will be a sentence space.
-Note that the behaviour of @acronym{UNIX} @code{troff} will be exactly
-that exhibited by GNU @code{troff} if a second argument is never given
-to the @code{ss} request.  In GNU @code{troff}, as in @acronym{UNIX}
-@code{troff}, a sentence should always be followed by either a newline
-or two spaces.
-
-@vindex .ss
-@vindex .sss
-The number registers @code{.ss} and @code{.sss} hold the values of the
-parameters set by the first and second arguments of the @code{ss}
-request.
+If two arguments are given to the @code{ss} request, the second
+argument sets the sentence space size.  If the second argument is not
+given, sentence space size is set to @var{word_space_size}.  The
+sentence space size is used in two circumstances: If the end of a
+sentence occurs at the end of a line in fill mode, then both an
+inter-word space and a sentence space are added; if two spaces follow
+the end of a sentence in the middle of a line, then the second space
+is a sentence space.  If a second argument is never given to the
+@code{ss} request, the behaviour of @acronym{UNIX} @code{troff} is the
+same as that exhibited by GNU @code{troff}.  In GNU @code{troff}, as
+in @acronym{UNIX} @code{troff}, a sentence should always be followed
+by either a newline or two spaces.
+
+The read-only number registers @code{.ss} and @code{.sss} hold the
+values of the parameters set by the first and second arguments of the
+@code{ss} request.
 
 The word space and sentence space values are associated with the current
 environment (@pxref{Environments}).
 
-This request is ignored in nroff mode; it is also ignored if there is no
-parameter.
-@end_Deffn
+Contrary to traditional Unix @code{troff}, this request is @emph{not}
+ignored if a tty output device is used; the given values are then
+rounded down to a multiple of@w{ }12.
+
+@c XXX xref implementation differences
+
+The request is ignored if there is no parameter.
+@endDefreq
 
 @cindex centering lines
 @cindex lines, centering
-@Deffn{Request, ce, [@var{nnn}]}
-Center text.  While the @w{@samp{.ad c}} request will also center text,
-it has the side effect of filling the text.  @code{ce} will not fill the
+@Defreq {ce, [@Var{nnn}]}
+@Defregx {.ce}
+Center text.  While the @w{@samp{.ad c}} request also centers text,
+it fills the text as well.  @code{ce} does not fill the
 text it affects.  This request causes a break.
 
-With no arguments, @code{ce} will center the next line of text.
-@var{nnn} specifies the number of lines to be centered.  If
-the argument is zero or negative, centering is disabled.
+The following example demonstrates the differences.
+Here the input:
+
+@Example
+.ll 4i
+.ce 1000
+This is a small text fragment which shows the differences
+between the `.ce' and the `.ad c' request.
+.ce 0
+
+.ad c
+This is a small text fragment which shows the differences
+between the `.ce' and the `.ad c' request.
+@endExample
+
+@noindent
+And here the result:
+
+@Example
+  This is a small text fragment which
+         shows the differences
+between the `.ce' and the `.ad c' request.
 
-@findex ll
-@findex in
-@findex ti
+  This is a small text fragment which
+shows the differences between the `.ce'
+        and the `.ad c' request.
+@endExample
+
+With no arguments, @code{ce} centers the next line of text.  @var{nnn}
+specifies the number of lines to be centered.  If the argument is zero
+or negative, centering is disabled.
+
+@rqindex ll
+@rqindex in
+@rqindex ti
 The basic length for centering text is the line length (as set with the
 @code{ll} request) minus the indentation (as set with the @code{in}
 request).  Temporary indentation is ignored.
 
-A common idiom is to turn on centering for a large number of lines, and
-to turn off centering after text to be centered.  This is useful for any
-request which takes a number of lines as an argument.
-
-@example
-.ce 1000
-replace this
-with
-something
-more interesting
-@dots{}
-.ce 0
-@end example
+As can be seen in the previous example, it is a common idiom to turn
+on centering for a large number of lines, and to turn off centering
+after text to be centered.  This is useful for any request which takes
+a number of lines as an argument.
 
-@vindex .ce
-The @code{.ce} number register contains the number of lines remaining to
-be centered, as set by the @code{ce} request.
-@end_Deffn
+The @code{.ce} read-only number register contains the number of lines
+remaining to be centered, as set by the @code{ce} request.
+@endDefreq
 
 @cindex justifying text
 @cindex text, justifying
 @cindex right-justifying
-@vindex .rj
-@Deffn{Request, rj, [@var{nnn}]}
+@Defreq {rj, [@Var{nnn}]}
+@Defregx {.rj}
 Justify unfilled text to the right margin.  Arguments are identical to
-the @code{ce} request.  The @code{.rj} number register is the number of
-lines to be right-justified as set by the @code{rj} request.  This
-request causes a line break.
-@end_Deffn
+the @code{ce} request.  The @code{.rj} read-only number register is
+the number of lines to be right-justified as set by the @code{rj}
+request.  This request causes a break.
+@endDefreq
 
 
 @c =====================================================================
 
-@node Manipulating Hyphenation, Manipulating Spacing, Manipulating Filling and Adjusting, Programming Tutorial
+@node Manipulating Hyphenation, Manipulating Spacing, Manipulating Filling and Adjusting, gtroff Reference
 @section Manipulating Hyphenation
 @cindex manipulating hyphenation
 @cindex hyphenation, manipulating
 
-As discussed in @ref{Hyphenation}, @code{gtroff} will hyphenate words.
+As discussed in @ref{Hyphenation}, @code{gtroff} hyphenates words.
 There are a number of ways to influence hyphenation.
 
-@Deffn{Request, hy, [@var{mode}]}
+@Defreq {hy, [@Var{mode}]}
+@Defregx {.hy}
 Enable hyphenation.  The request has an optional numeric argument,
 @var{mode}, to restrict hyphenation if necessary:
 
@@ -4008,52 +4363,54 @@ Values in the previous table are additive.  For example, the value@w{
 }12 causes @code{gtroff} to neither hyphenate the last two nor the first
 two characters of a word.
 
-@vindex .hy
 @cindex hyphenation restrictions register
-The current hyphenation restrictions can be found in the number register
-@samp{.hy}.
+The current hyphenation restrictions can be found in the read-only
+number register @samp{.hy}.
 
 The hyphenation mode is associated with the current environment
 (@pxref{Environments}).
-@end_Deffn
+@endDefreq
 
-@Deffn{Request, nh, }
-Disable hyphenation (i.e., set the hyphenation mode to zero).  Note that
-the hyphenation mode of the last call to @code{hy} is not remembered.
+@Defreq {nh, }
+Disable hyphenation (i.e., set the hyphenation mode to zero).  Note
+that the hyphenation mode of the last call to @code{hy} is not
+remembered.
 
 The hyphenation mode is associated with the current environment
 (@pxref{Environments}).
-@end_Deffn
+@endDefreq
 
-@vindex .hlc
-@vindex .hlm
-@findex \%
+@esindex \%
 @cindex explicit hyphens
 @cindex hyphen, explicit
 @cindex consecutive hyphenated lines
 @cindex lines, consecutive hyphenated
 @cindex hyphenated lines, consecutive
-@Deffn{Request, hlm, [@var{nnn}]}
-Set the maximum number of consecutive hyphenated lines to @var{nnn}.  If
-this number is negative, there is no maximum.  The default value is@w{
-}-1 if @var{nnn} is omitted.  This value is associated with the current
-environment (@pxref{Environments}).  Only lines output from a given
-environment count towards the maximum associated with that environment.
-Hyphens resulting from @code{\%} are counted; explicit hyphens are not.
+@Defreq {hlm, [@Var{nnn}]}
+@Defregx {.hlm}
+@Defregx {.hlc}
+Set the maximum number of consecutive hyphenated lines to @var{nnn}.
+If this number is negative, there is no maximum.  The default value
+is@w{ }@minus{}1 if @var{nnn} is omitted.  This value is associated
+with the current environment (@pxref{Environments}).  Only lines
+output from a given environment count towards the maximum associated
+with that environment.  Hyphens resulting from @code{\%} are counted;
+explicit hyphens are not.
 
 The current setting of @code{hlm} is available in the @code{.hlm}
-register.  Also the number of immediately preceding consecutive
-hyphenated lines are available in the number register @samp{.hlc}.
-@end_Deffn
+read-only number register.  Also the number of immediately preceding
+consecutive hyphenated lines are available in the read-only number
+register @samp{.hlc}.
+@endDefreq
 
-@Deffn{Request, hw, word1 word2 @dots{}}
+@Defreq {hw, word1 word2 @dots{}}
 Define how @var{word1}, @var{word2}, etc.@: are to be hyphenated.  The
 words must be given with hyphens at the hyphenation points.  For
 example:
 
-@example
+@Example
 .hw in-sa-lub-rious
-@end example
+@endExample
 
 @noindent
 Besides the space character, any character whose hyphenation code value
@@ -4062,7 +4419,7 @@ documentation for the @code{hcode} request below for more information).
 In addition, this request can be used more than once.
 
 Hyphenation exceptions specified with the @code{hw} request are
-associated with the current hyphenation language; it will cause an error
+associated with the current hyphenation language; it causes an error
 if there is no current hyphenation language.
 
 This request is ignored if there is no parameter.
@@ -4070,38 +4427,39 @@ This request is ignored if there is no parameter.
 In old versions of @code{troff} there was a limited amount of space to
 store such information; fortunately, with @code{gtroff}, this is no
 longer a restriction.
-@end_Deffn
+@endDefreq
 
 @cindex hyphenation character
 @cindex character, hyphenation
 @cindex disabling hyphenation
 @cindex hyphenation, disabling
-@Deffn{Escape, \\%, }
-To tell @code{gtroff} how to hyphenate words on the fly, the @code{\%}
-escape, also known as the @dfn{hyphenation character}, can be used.
-Preceding a word with this character will prevent it from being
-hyphenated, putting it in a word will indicate to @code{gtroff} that the
-word may be hyphenated at that point.  Note that this mechanism will
-only affect that one occurrence of the word; to change the hyphenation
-of a word for the entire document, use the @code{hw} request.
-@end_Deffn
-
-@Deffn{Request, hc, [@var{char}]}
-Change the hyphenation character to @var{char}.  This character will
-then work the same as the @code{\%} escape, and thus, no longer appear
-in the output.  Without an argument, @code{hc} will reset the
-hyphenation character to be @code{\%} (the default) only.
+@Defesc {\\%, , , }
+To tell @code{gtroff} how to hyphenate words on the fly, use the
+@code{\%} escape, also known as the @dfn{hyphenation character}.
+Preceding a word with this character prevents it from being
+hyphenated; putting it inside a word indicates to @code{gtroff} that
+the word may be hyphenated at that point.  Note that this mechanism
+only affects that one occurrence of the word; to change the
+hyphenation of a word for the entire document, use the @code{hw}
+request.
+@endDefesc
+
+@Defreq {hc, [@Var{char}]}
+Change the hyphenation character to @var{char}.  This character then
+works the same as the @code{\%} escape, and thus, no longer appears in
+the output.  Without an argument, @code{hc} resets the hyphenation
+character to be @code{\%} (the default) only.
 
 The hyphenation character is associated with the current environment
 (@pxref{Environments}).
-@end_Deffn
+@endDefreq
 
 @cindex hyphenation patterns
 @cindex patterns for hyphenation
-@Deffn{Request, hpf, pattern_file}
-Read in a file of hyphenation patterns.  This file will be searched for
-in the same way as @file{tmac.@var{name}} is searched for if the
-@option{-m@var{name}} option is specified.
+@Defreq {hpf, pattern_file}
+Read in a file of hyphenation patterns.  This file is searched for in
+the same way as @file{@var{name}.tmac} (or @file{tmac.@var{name}}) is
+searched for if the @option{-m@var{name}} option is specified.
 
 It should have the same format as the argument to the @code{\patterns}
 primitive in @TeX{} (without using @TeX{}'s macro expansion); the
@@ -4112,7 +4470,7 @@ continues to the end of the line.
 If no @code{hpf} request is specified (either in the document or in a
 macro package), @code{gtroff} won't hyphenate at all.
 
-@findex hla
+@rqindex hla
 @pindex troffrc
 @pindex troffrc-end
 @pindex hyphen.us
@@ -4122,85 +4480,90 @@ invoked by the @file{troffrc} or @file{troffrc-end} file; by default,
 @file{troffrc} loads hyphenation patterns for American English (in file
 @file{hyphen.us}).
 
-@code{hpf} will cause an error if there is no current hyphenation
+Invoking @code{hpf} causes an error if there is no current hyphenation
 language.
-@end_Deffn
+@endDefreq
 
 @cindex hyphenation code
 @cindex code, hyphenation
-@Deffn{Request, hcode, c1 code1 c2 code2 @dots{}}
-Sets the hyphenation code of character @var{c1} to @var{code1}, that of
-@var{c2} to @var{code2}, etc.  A hyphenation code must be a single input
-character (not a special character) other than a digit or a space.
-Initially each lower-case letter (@samp{a}-@samp{z}) has its hyphenation
-set to itself, and each upper-case letter (@samp{A}-@samp{Z}) has a
-hyphenation code which is the lower-case version of itself.
-
-This request will be ignored if it has no parameter.
-@end_Deffn
+@Defreq {hcode, c1 code1 c2 code2 @dots{}}
+Set the hyphenation code of character @var{c1} to @var{code1}, that of
+@var{c2} to @var{code2}, etc.  A hyphenation code must be a single
+input character (not a special character) other than a digit or a
+space.  Initially each lower-case letter (@samp{a}-@samp{z}) has its
+hyphenation set to itself, and each upper-case letter
+(@samp{A}-@samp{Z}) has a hyphenation code which is the lower-case
+version of itself.
+
+This request is ignored if it has no parameter.
+@endDefreq
 
 @cindex hyphenation margin
 @cindex margin for hyphenation
-@findex ad
-@Deffn{Request, hym, [@var{length}]}
+@rqindex ad
+@Defreq {hym, [@Var{length}]}
+@Defregx {.hym}
 Set the (right) hyphenation margin to @var{length}.  If the current
-adjustment mode is not@w{ }@samp{b}, the line will not be hyphenated if
-it is shorter than @var{length}.  Without argument, the hyphenation
-margin will be reset to its default value, which is@w{ }0.  The default
-scaling indicator for this request is@w{ }@code{m}.  The hyphenation
-margin is associated with the current environment
+adjustment mode is not @samp{b} or@w{ }@samp{n}, the line is not
+hyphenated if it is shorter than @var{length}.  Without an argument,
+the hyphenation margin is reset to its default value, which is@w{ }0.
+The default scaling indicator for this request is@w{ }@code{m}.  The
+hyphenation margin is associated with the current environment
 (@pxref{Environments}).
 
-A negative argument will reset the hyphenation margin to zero, emitting
+A negative argument resets the hyphenation margin to zero, emitting
 a warning of type @samp{range}.
 
-@vindex .hym
 @cindex current hyphenation margin register
-The current hyphenation margin is available in the @code{.hym} register.
-@end_Deffn
+The current hyphenation margin is available in the @code{.hym} read-only
+number register.
+@endDefreq
 
 @cindex hyphenation space
-@findex ad
-@Deffn{Request, hys, [@var{hyphenation_space}]}
+@rqindex ad
+@Defreq {hys, [@Var{hyphenation_space}]}
+@Defregx {.hys}
 Set the hyphenation space to @var{hyphenation_space}.  If the current
-adjustment mode is@w{ }@samp{b}, don't hyphenate the line if it
-can be justified by adding no more than @var{hyphenation_space} extra
-space to each word space.  Without argument, the hyphenation space is
-set to its default value, which is@w{ }0.  The default scaling indicator
-for this request is@w{ }@code{m}.  The hyphenation space is associated
-with the current environment (@pxref{Environments}).
-
-A negative argument will reset the hyphenation space to zero, emitting a
+adjustment mode is @samp{b} or@w{ }@samp{n}, don't hyphenate the line
+if it can be justified by adding no more than @var{hyphenation_space}
+extra space to each word space.  Without argument, the hyphenation
+space is set to its default value, which is@w{ }0.  The default
+scaling indicator for this request is@w{ }@code{m}.  The hyphenation
+space is associated with the current environment
+(@pxref{Environments}).
+
+A negative argument resets the hyphenation space to zero, emitting a
 warning of type @samp{range}.
 
-@vindex .hys
 @cindex current hyphenation space register
-The current hyphenation space is available in the @code{.hys} register.
-@end_Deffn
+The current hyphenation space is available in the @code{.hys} read-only
+number register.
+@endDefreq
 
 @cindex soft hyphen character
 @cindex character, soft hyphen
 @glindex hy
-@findex char
-@findex tr
-@Deffn{Request, shc, [@var{char}]}
+@rqindex char
+@rqindex tr
+@Defreq {shc, [@Var{char}]}
 Set the soft hyphen character to @var{char}.  If the argument is
-omitted, the soft hyphen character will be set to the default character
+omitted, the soft hyphen character is set to the default character
 @code{\(hy} (this is the start-up value of @code{gtroff} also).  The
-soft hyphen character is the character which will be inserted when a
-word is hyphenated at a line break.  If the soft hyphen character does
-not exist in the font of the character immediately preceding a potential
-break point, then the line will not be broken at that point.  Neither
+soft hyphen character is the character that is inserted when a word is
+hyphenated at a line break.  If the soft hyphen character does not
+exist in the font of the character immediately preceding a potential
+break point, then the line is not broken at that point.  Neither
 definitions (specified with the @code{char} request) nor translations
 (specified with the @code{tr} request) are considered when finding the
 soft hyphen character.
-@end_Deffn
+@endDefreq
 
-@findex hpf
-@findex hw
+@rqindex hpf
+@rqindex hw
 @pindex troffrc
 @pindex troffrc-end
-@Deffn{Request, hla, language}
+@Defreq {hla, language}
+@Defregx {.hla}
 Set the current hyphenation language to the string @var{language}.
 Hyphenation exceptions specified with the @code{hw} request and
 hyphenation patterns specified with the @code{hpf} request are both
@@ -4209,111 +4572,120 @@ request is usually invoked by the @file{troffrc} or the
 @file{troffrc-end} files; @file{troffrc} sets the default language to
 @samp{us}.
 
-@vindex .hla
 @cindex current hyphenation language register
 The current hyphenation language is available as a string in the
 read-only number register @samp{.hla}.
 
-@example
+@Example
 .ds curr_language \n[.hla]
 \*[curr_language]
     @result{} us
-@end example
-@end_Deffn
+@endExample
+@endDefreq
 
 
 @c =====================================================================
 
-@node Manipulating Spacing, Tabs and Fields, Manipulating Hyphenation, Programming Tutorial
+@node Manipulating Spacing, Tabs and Fields, Manipulating Hyphenation, gtroff Reference
 @section Manipulating Spacing
 @cindex manipulating spacing
 @cindex spacing, manipulating
 
-@Deffn{Request, sp, [@var{distance}]}
-Space downwards @var{distance}.  With no argument it will advance 1@w{
-}line.  A negative argument will cause @code{gtroff} to move up the page
+@Defreq {sp, [@Var{distance}]}
+Space downwards @var{distance}.  With no argument it advances 1@w{
+}line.  A negative argument causes @code{gtroff} to move up the page
 the specified distance.  If the argument is preceded by a @samp{|}
-@code{gtroff} will move that distance from the top of the page.  This
+then @code{gtroff} moves that distance from the top of the page.  This
 request causes a line break.  The default scaling indicator is@w{
 }@code{v}.
-@end_Deffn
+@endDefreq
 
 @cindex double-spacing
-@Deffn{Request, ls, [@var{nnn}]}
-Output @w{@var{nnn}-1} blank lines after each line of text.  With no
-argument @code{gtroff} will use the previous value before the last
-@code{ls} call.
+@Defreq {ls, [@Var{nnn}]}
+@Defregx {.L}
+Output @w{@var{nnn}@minus{}1} blank lines after each line of text.
+With no argument, @code{gtroff} uses the previous value before the
+last @code{ls} call.
 
-@example
+@Example
 .ls 2    \" This causes double-spaced output
 .ls 3    \" This causes triple-spaced output
 .ls      \" Again double spaced
-@end example
+@endExample
 
 The line spacing is associated with the current environment
 (@pxref{Environments}).
 
-@vindex .L
 @cindex current line spacing register
-The number register @code{.L} contains the current line spacing setting.
-@end_Deffn
-
-@Deffn{Escape, \\x, spacing}
-Sometimes, extra vertical spacing is only needed occasionally, e.g.@: to
-allow space for a tall construct (like an equation).  The @code{\x}
-escape will do this.  The escape is given a numerical argument, usually
+The read-only number register @code{.L} contains the current line
+spacing setting.
+@endDefreq
+
+@c XXX document \n[nl]
+@c XXX document \n[nl] == -1 if vertical position is zero
+
+@Defesc {\\x, ', spacing, '}
+@Defregx {.a}
+Sometimes, extra vertical spacing is only needed occasionally, e.g.@:
+to allow space for a tall construct (like an equation).  The @code{\x}
+escape does this.  The escape is given a numerical argument, usually
 enclosed in quotes (like @samp{\x'3p'}); the default scaling indicator
-is@w{ }@code{v}.  If this number is positive extra vertical space will
-be inserted below the current line.  A negative number will add space
-above.  If this escape is used multiple times on the same line, the
-maximum of the values is used.
+is@w{ }@code{v}.  If this number is positive extra vertical space is
+inserted below the current line.  A negative number adds space above.
+If this escape is used multiple times on the same line, the maximum of
+the values is used.
 
 @xref{Escapes}, for details on parameter delimiting characters.
 
-@vindex .a
 @cindex extra vertical line space register
-The @code{.a} number register contains the most recent (nonnegative)
-extra vertical line space.
+The @code{.a} read-only number register contains the most recent
+(nonnegative) extra vertical line space.
 
 @c XXX
 @ignore
-@example
+@Example
 ... example of inline equation ...
-@end example
+@endExample
 @end ignore
-@end_Deffn
+@endDefesc
 
-@findex sp
+@rqindex sp
 @cindex no-space mode
 @cindex mode, no-space
 @cindex blank lines, disabling
 @cindex lines, blank, disabling
-@Deffn{Request, ns, }
-Enable @dfn{no-space mode}.  In this mode, spacing (either via @code{sp}
-or via blank lines) is disabled.  The @code{bp} request to advance to
-the next page is also disabled, except if it is accompanied by a page
-number (see @ref{Page Control}, for more information).  This mode will
-end when actual text is output or the @code{rs} request is encountered.
-
+@Defreq {ns, }
+Enable @dfn{no-space mode}.  In this mode, spacing (either via
+@code{sp} or via blank lines) is disabled.  The @code{bp} request to
+advance to the next page is also disabled, except if it is accompanied
+by a page number (see @ref{Page Control}, for more information).  This
+mode ends when actual text is output or the @code{rs} request is
+encountered.
+
+@cindex top-level diversion
+@cindex diversion, top-level
 This request is useful for macros which want to avoid that subsequent
 macros inadvertently insert some vertical space before the text starts
 (for example, to set up the first paragraph after a section header).  It
-is associated with the current diversion level.
+has no effect if not called within the top-level diversion
+(@pxref{Diversions}).
 
 @c XXX xref
-@end_Deffn
+@endDefreq
 
-@Deffn{Request, rs, }
-Disable no-space mode.  This request is associated with the current
-diversion level.
+@cindex top-level diversion
+@cindex diversion, top-level
+@Defreq {rs, }
+Disable no-space mode.  It has no effect if not called within the
+top-level diversion (@pxref{Diversions}).
 
 @c XXX xref
-@end_Deffn
+@endDefreq
 
 
 @c =====================================================================
 
-@node Tabs and Fields, Character Translations, Manipulating Spacing, Programming Tutorial
+@node Tabs and Fields, Character Translations, Manipulating Spacing, gtroff Reference
 @section Tabs and Fields
 @cindex tabs and fields
 @cindex fields and tabs
@@ -4323,33 +4695,34 @@ A tab character (@acronym{ASCII} char@w{ }9, @acronym{EBCDIC} char@w{
 }5) causes a horizontal movement to the next tab stop (much
 like it did on a typewriter).
 
-@Deffn{Escape, \\t, }
+@Defesc {\\t, , , }
 This escape is a non-interpreted tab character.  In copy mode
 (@pxref{Copy-in Mode}), @code{\t} is the same as a real tab character.
-@end_Deffn
+@endDefesc
 
-@Deffn{Request, ta, [@var{n1} @var{n2} @dots{} @var{nn} @t{T} @var{r1} @var{r2} @dots{} @var{rn}]}
+@Defreq {ta, [@Var{n1} @Var{n2} @dots{} @Var{nn} @t{T} @Var{r1} @Var{r2} @dots{} @Var{rn}]}
+@Defregx {.tabs}
 Change tab stop positions.  This request takes a series of tab
 specifiers as arguments (optionally divided into two groups with the
-letter @samp{T}) which indicate where each tab stop is to be (overriding
-any previous settings).
+letter @samp{T}) which indicate where each tab stop is to be
+(overriding any previous settings).
 
 Tab stops can be specified absolutely, i.e., as the distance from the
-left margin.  For example, the following will set 6@w{ }tab stops every
+left margin.  For example, the following sets 6@w{ }tab stops every
 one inch.
 
-@example
+@Example
 .ta 1i 2i 3i 4i 5i 6i
-@end example
+@endExample
 
-Tab stops can also be specified relatively (using a leading @samp{+})
-which means that the specified tab stop will be set that distance from
+Tab stops can also be specified using a leading @samp{+}
+which means that the specified tab stop is set relative to
 the previous tab stop.  For example, the following is equivalent to the
 previous example.
 
-@example
+@Example
 .ta 1i +1i +1i +1i +1i +1i
-@end example
+@endExample
 
 @code{gtroff} supports an extended syntax to specify repeat values after
 the @samp{T} mark (these values are always taken as relative) -- this is
@@ -4357,9 +4730,9 @@ the usual way to specify tabs set at equal intervals.  The following is,
 yet again, the same as the previous examples.  It does even more since
 it defines an infinite number of tab stops separated by one inch.
 
-@example
+@Example
 .ta T 1i
-@end example
+@endExample
 
 Now we are ready to interpret the full syntax given at the beginning:
 Set tabs at positions @var{n1}, @var{n2}, @dots{}, @var{nn} and then set
@@ -4375,9 +4748,9 @@ may be justified to the right or left or centered in the column.  This
 is specified by appending @samp{R}, @samp{L}, or @samp{C} to the tab
 specifier.  The default justification is @samp{L}.  Example:
 
-@example
+@Example
 .ta 1i 2iC 2iR
-@end example
+@endExample
 
 Some notes:
 
@@ -4389,22 +4762,22 @@ The default unit of the @code{ta} request is @samp{m}.
 A tab stop is converted into a non-breakable horizontal movement which
 can be neither stretched nor squeezed.  For example,
 
-@example
+@Example
 .ds foo a\tb\tc
 .ta T 5i
 \*[foo]
-@end example
+@endExample
 
 @noindent
 creates a single line which is a bit longer than 10@w{ }inches (a string
 is used to show exactly where the tab characters are).  Now consider the
 following:
 
-@example
+@Example
 .ds bar a\tb b\tc
 .ta T 5i
 \*[bar]
-@end example
+@endExample
 
 @noindent
 @code{gtroff} first converts the tab stops of the line into unbreakable
@@ -4415,10 +4788,10 @@ the user wants.
 @item
 Superfluous tabs (i.e., tab characters which do not correspond to a tab
 stop) are ignored except the first one which delimits the characters
-belonging to the last tab stop for right-justifying resp.@: centering.
+belonging to the last tab stop for right-justifying or centering.
 Consider the following example
 
-@example
+@Example
 .ds Z   foo\tbar\tfoo
 .ds ZZ  foo\tbar\tfoobar
 .ds ZZZ foo\tbar\tfoo\tbar
@@ -4429,16 +4802,16 @@ Consider the following example
 .br
 \*[ZZZ]
 .br
-@end example
+@endExample
 
 @noindent
 which produces the following output:
 
-@example
+@Example
 foo                 bar              foo
 foo                 bar           foobar
 foo                 bar              foobar
-@end example
+@endExample
 
 @noindent
 The first line right-justifies the second `foo' relative to the tab
@@ -4451,41 +4824,42 @@ Tab stops are associated with the current environment
 (@pxref{Environments}).
 
 @item
-Calling @code{ta} without an argument will unset all tab stops.
+Calling @code{ta} without an argument removes all tab stops.
 
 @item
-@cindex tab stops, in nroff mode
-The start-up value of @code{gtroff} is @w{@samp{T 0.5i}}.  This value is
-used even in nroff mode (contrary to @acronym{UNIX} @code{nroff} which
-has tab stops preset every 0.8@dmn{i}).
+@cindex tab stops, for tty output devices
+The start-up value of @code{gtroff} is @w{@samp{T 0.5i}}.  This value
+is used even for tty output devices (contrary to @acronym{UNIX}
+@code{nroff} which has tab stops preset every 0.8@dmn{i}).
+
+@c XXX xref implementation differences
 @end itemize
 
-@vindex .tabs
 @cindex current tab settings register
-The number register @code{.tabs} contains a string representation of the
-current tab settings suitable for use as an argument to the @code{ta}
-request.
+The read-only number register @code{.tabs} contains a string
+representation of the current tab settings suitable for use as an
+argument to the @code{ta} request.
 
-@example
+@Example
 .ds tab-string \n[.tabs]
 \*[tab-string]
     @result{} T120u
-@end example
-@end_Deffn
-
-@cindex tab repitition character
-@cindex character, tab repitition
-@Deffn{Request, tc, [@var{fill-char}]}
-Normally @code{gtroff} will fill the space to the next tab stop with
-space.  This can be changed with the @code{tc} request.  With no
-argument @code{gtroff} will revert to using space, which is the default.
-The value of this @dfn{tab repitition} character is associated with the
-current environment (@pxref{Environments}).
-@end_Deffn
+@endExample
+@endDefreq
+
+@cindex tab repetition character
+@cindex character, tab repetition
+@Defreq {tc, [@Var{fill-char}]}
+Normally @code{gtroff} fills the space to the next tab stop with
+whitespace.  This can be changed with the @code{tc} request.  With no
+argument @code{gtroff} reverts to using whitespace, which is the
+default.  The value of this @dfn{tab repetition} character is
+associated with the current environment (@pxref{Environments}).
+@endDefreq
 
 @menu
-* Leaders::                     
-* Fields::                      
+* Leaders::
+* Fields::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -4498,7 +4872,7 @@ Sometimes it may may be desirable to use the @code{tc} request to fill a
 particular tab stop with a given character (for example dots in a table
 of contents), but also normal tab stops on the rest of the line.  For
 this @code{gtroff} provides an alternate tab mechanism, called
-@dfn{leaders} which will do just that.
+@dfn{leaders} which does just that.
 
 @cindex leader character
 A leader character (character code@w{ }1) behaves similarly to a tab
@@ -4506,21 +4880,21 @@ character: It moves to the next tab stop.  The only difference is that
 for this movement, the fill character defaults to a period character and
 not to space.
 
-@Deffn{Escape, \\a, }
+@Defesc {\\a, , , }
 This escape is a non-interpreted leader character.  In copy mode
 (@pxref{Copy-in Mode}), @code{\a} is the same as a real leader
 character.
-@end_Deffn
-
-@cindex leader repitition character
-@cindex character, leader repitition
-@Deffn{Request, lc, [@var{fill-char}]}
-The character that will be repeated can be declared with the @code{lc}
-request.  Without an argument, leaders will act the same as tabs (i.e.,
-using space for filling).  @code{gtroff}'s start-up value is @samp{.}.
-The value of this @dfn{leader repitition} character is associated with
-the current environment (@pxref{Environments}).
-@end_Deffn
+@endDefesc
+
+@cindex leader repetition character
+@cindex character, leader repetition
+@Defreq {lc, [@Var{fill-char}]}
+Declare the leader character.  Without an argument, leaders act the
+same as tabs (i.e., using whitespace for filling).  @code{gtroff}'s
+start-up value is @samp{.}.  The value of this @dfn{leader repetition}
+character is associated with the current environment
+(@pxref{Environments}).
+@endDefreq
 
 @cindex table of contents
 @cindex contents, table of
@@ -4529,19 +4903,19 @@ that the section number is one tab stop, the title is the second with
 the remaining space being filled with a line of dots, and then the page
 number slightly separated from the dots.
 
-@example
+@Example
 .ds entry 1.1\tFoo\a\t12
 .lc .
 .ta 1i 5i +.25i
 \*[entry]
-@end example
+@endExample
 
 @noindent
 This produces
 
-@example
+@Example
 1.1  Foo..........................................  12
-@end example
+@endExample
 
 @c ---------------------------------------------------------------------
 
@@ -4566,43 +4940,43 @@ lengths plus the stretchable space equal to the field width.  If more
 than one padding character is inserted, the available space is evenly
 distributed among them.
 
-@Deffn{Request, fc, [@var{delim-char} [@var{padding-char}]]}
+@Defreq {fc, [@Var{delim-char} [@Var{padding-char}]]}
 Define a delimiting and a padding character for fields.  If the latter
 is missing, the padding character defaults to a space character.  If
 there is no argument at all, the field mechanism is disabled (which is
-the default).  Note that contrary to e.g.@: the tab repitition
+the default).  Note that contrary to e.g.@: the tab repetition
 character, delimiting and padding characters are not associated to the
 current environment (@pxref{Environments}).
 
 Example:
 
-@example
+@Example
 .fc # ^
 .ta T 3i
 #foo^bar^smurf#
 .br
 #foo^^bar^smurf#
-@end example
+@endExample
 
 @noindent
 and here the result:
 
-@example
+@Example
 foo         bar          smurf
 foo            bar       smurf
-@end example
-@end_Deffn
+@endExample
+@endDefreq
 
 
 @c =====================================================================
 
-@node Character Translations, Troff and Nroff Mode, Tabs and Fields, Programming Tutorial
+@node Character Translations, Troff and Nroff Mode, Tabs and Fields, gtroff Reference
 @section Character Translations
 @cindex character translations
 @cindex translations of characters
 
-@findex .
-@findex '
+@rqindex .
+@rqindex '
 @cindex control character
 @cindex character, control
 @cindex no-break control character
@@ -4612,29 +4986,30 @@ The control character (@samp{.}) and the no-break control character
 (@samp{'}) can be changed with the @code{cc} and @code{c2} requests,
 respectively.
 
-@Deffn{Request, cc, [@var{c}]}
+@Defreq {cc, [@Var{c}]}
 Set the control character to @var{c}.  With no argument the default
 control character @samp{.} is restored.  The value of the control
 character is associated with the current environment
 (@pxref{Environments}).
-@end_Deffn
+@endDefreq
 
-@Deffn{Request, c2, [@var{c}]}
+@Defreq {c2, [@Var{c}]}
 Set the no-break control character to @var{c}.  With no argument the
 default control character @samp{'} is restored.  The value of the
 no-break control character is associated with the current environment
 (@pxref{Environments}).
-@end_Deffn
+@endDefreq
 
-@findex \
-@Deffn{Request, eo, }
-Disable the escape mechanism completely.  After executing this request,
-the backslash character @samp{\} no longer starts an escape sequence.
+@esindex \\
+@Defreq {eo, }
+Disable the escape mechanism completely.  After executing this
+request, the backslash character @samp{\} no longer starts an escape
+sequence.
 
 This request can be very helpful in writing macros since it is not
 necessary then to double the escape character.  Here an example:
 
-@example
+@Example
 .\" This is a simplified version of the
 .\" .BR request from the man macro package
 .eo
@@ -4649,27 +5024,27 @@ necessary then to double the escape character.  Here an example:
 .  ft R
 ..
 .ec
-@end example
-@end_Deffn
+@endExample
+@endDefreq
 
 @cindex escape character
 @cindex character, escape
-@Deffn{Request, ec, [@var{c}]}
+@Defreq {ec, [@Var{c}]}
 Set the escape character to @var{c}.  With no argument the default
-escape character @samp{\} is restored.  It can be also used to re-enable
-the escape mechanism after an @code{eo} request.
+escape character @samp{\} is restored.  It can be also used to
+re-enable the escape mechanism after an @code{eo} request.
 
-Note that changing the escape character globally will likely break macro
-packages since @code{gtroff} has no mechanism (like @TeX{}) to `intern'
-macros, i.e., to convert a macro definition into an internal form which
-is independent of its representation.  If a macro is called, it will be
-executed literally.
-@end_Deffn
+Note that changing the escape character globally will likely break
+macro packages since @code{gtroff} has no mechanism (like @TeX{}) to
+`intern' macros, i.e., to convert a macro definition into an internal
+form which is independent of its representation.  If a macro is
+called, it is executed literally.
+@endDefreq
 
-@Deffn{Escape, \\e, }
+@Defesc {\\e, , , }
 This escape sequence prints the current escape character (which is the
 backslash character @samp{\} by default).
-@end_Deffn
+@endDefesc
 
 A @dfn{translation} is a mapping of an input character to an output
 character.  The default mappings are given in the font definition files
@@ -4678,24 +5053,24 @@ with @code{tr} and in the font definition files) occur at output time,
 i.e., the input character gets assigned the metric information of the
 mapped output character.
 
-@Deffn{Request, tr, @var{a}@var{b}@var{c}@var{d}@dots{}}
+@Defreq {tr, @Var{a}@Var{b}@Var{c}@Var{d}@dots{}}
 Translate character @var{a} to @var{b}, character @var{c} to @var{d},
-etc.  If there is an odd number of arguments, the last one will be
+etc.  If there is an odd number of arguments, the last one is
 translated to the space character.
 
 Some notes:
 
 @itemize @bullet
 @item
-@findex \(
-@findex \[
-@findex \'
-@findex \`
-@findex \-
-@findex \_
-@findex \C
-@findex \N
-@findex char
+@esindex \(
+@esindex \[
+@esindex \'
+@esindex \`
+@esindex \-
+@esindex \_
+@esindex \C
+@esindex \N
+@rqindex char
 @cindex special character
 @cindex character, special
 @cindex numbered character
@@ -4706,13 +5081,14 @@ characters defined with the @code{char} request, and numbered characters
 (@code{\N'@var{xxx}'}) can be translated also.
 
 @item
-@findex \e
+@esindex \e
 The @code{\e} escape can be translated also.
 
 @item
-@findex \%
-Characters can be mapped onto the @code{\%} escape (but @code{\%} can't
-be mapped onto another character).
+@esindex \%
+@esindex \~
+Characters can be mapped onto the @code{\%} and @code{\~} escapes (but
+@code{\%} and @code{\~} can't be mapped onto another character).
 
 @item
 @cindex backspace character
@@ -4723,45 +5099,45 @@ be mapped onto another character).
 @cindex character, newline
 @cindex tab character
 @cindex character, tab
-@findex \a
-@findex \t
+@esindex \a
+@esindex \t
 The following characters can't be translated: space (with one exception,
 see below), backspace, newline, leader (and @code{\a}), tab (and
 @code{\t}).
 
 @item
-@findex shc
+@rqindex shc
 Translations are not considered for finding the soft hyphen character
 set with the @code{shc} request.
 
 @item
-@findex \&
+@esindex \&
 The character pair @samp{@var{c}\&} (this is an arbitrary character@w{
-}@var{c} followed by the zero width space character) will map this
+}@var{c} followed by the zero width space character) maps this
 character to nothing.
 
-@example
+@Example
 .tr a\&
 foo bar
     @result{} foo br
-@end example
+@endExample
 
 @noindent
 It is even possible to map the space character to nothing:
 
-@example
+@Example
 .tr aa \&
 foo bar
     @result{} foobar
-@end example
+@endExample
 
 @noindent
 As shown in the example, the space character can't be the first
 character pair as an argument of @code{tr}.  Additionally, it is not
 possible to map the space character to any other character; requests
-like @w{@samp{.tr aa x}} will undo @w{@samp{.tr aa \&}} instead.
+like @w{@samp{.tr aa x}} undo @w{@samp{.tr aa \&}} instead.
 
-If justification is active, lines will be justified inspite of the
+If justification is active, lines are justified in spite of the
 `empty' space character (but there is no minimal distance, i.e.@: the
 space character, between words).
 
@@ -4776,33 +5152,35 @@ string), it is no longer affected by @code{tr}.
 @item
 Without an argument, the @code{tr} request is ignored.
 @end itemize
-@end_Deffn
+@endDefreq
 
-@findex \!@r{, and @code{trnt}}
-@Deffn{Request, trnt, @var{a}@var{b}@var{c}@var{d}@dots{}}
+@esindex \!
+@cindex @code{\!}, and @code{trnt}
+@Defreq {trnt, @Var{a}@Var{b}@Var{c}@Var{d}@dots{}}
 @code{trnt} is the same as the @code{tr} request except that the
-translations do not apply to text that is transparently throughput into
-a diversion with @code{\!}.  @xref{Diversions}, for more information.
+translations do not apply to text that is transparently throughput
+into a diversion with @code{\!}.  @xref{Diversions}, for more
+information.
 
 For example,
 
-@example
+@Example
 .tr ab
 .di x
 \!.tm a
 .di
 .x
-@end example
+@endExample
 
 @noindent
-will print @samp{b}; if @code{trnt} is used instead of @code{tr} it will
-print @samp{a}.
-@end_Deffn
+prints @samp{b} to the standard error stream; if @code{trnt} is used
+instead of @code{tr} it prints @samp{a}.
+@endDefreq
 
 
 @c =====================================================================
 
-@node Troff and Nroff Mode, Line Layout, Character Translations, Programming Tutorial
+@node Troff and Nroff Mode, Line Layout, Character Translations, gtroff Reference
 @section Troff and Nroff Mode
 @cindex troff mode
 @cindex mode, troff
@@ -4811,43 +5189,67 @@ print @samp{a}.
 
 Originally, @code{nroff} and @code{troff} were two separate programs,
 the former for tty output, the latter for everything else.  With GNU
-@code{troff}, both programs are merged into one executable.
-
-Usually, a macro package can be used with both @code{nroff} and
-@code{troff}.  Nevertheless, it is sometimes necessary to make a
-distinction between the two programs (resp.@: modes), and @code{gtroff}
-provides two built-in conditions @samp{n} and @samp{t} for the
-@code{if}, @code{ie}, and @code{while} requests to decide whether
-@code{gtroff} shall behave like @code{nroff} or like @code{troff}.
+@code{troff}, both programs are merged into one executable, sending
+its output to a device driver (@code{grotty} for tty devices,
+@code{grops} for @sc{PostScript}, etc.) which interprets the
+intermediate output of @code{gtroff}.  For @acronym{UNIX} @code{troff}
+it makes sense to talk about @dfn{Nroff mode} and @dfn{Troff mode}
+since the differences are hardcoded.  For GNU @code{troff}, this
+distinction is not appropriate because @code{gtroff} simply takes the
+information given in the font files for a particular device without
+handling requests specially if a tty output device is used.
+
+Usually, a macro package can be used with all output devices.
+Nevertheless, it is sometimes necessary to make a distinction between
+tty and non-tty devices: @code{gtroff} provides two built-in
+conditions @samp{n} and @samp{t} for the @code{if}, @code{ie}, and
+@code{while} requests to decide whether @code{gtroff} shall behave
+like @code{nroff} or like @code{troff}.
 
 @pindex troffrc
 @pindex troffrc-end
-@Deffn{Request, troff, }
+@Defreq {troff, }
 Make the @samp{t} built-in condition true (and the @samp{n} built-in
-condition false) for @code{if}, @code{ie}, and @code{while} conditional
-requests.  This is the default if @code{gtroff} (@emph{not}
-@code{groff}) is started with the @option{-R} switch to avoid loading of
-the start-up files @file{troffrc} and @file{troffrc-end}.  Without
-@option{-R}, @code{gtroff} stays in troff mode if the output device is
-not a tty (e.g.@: `ps').
-@end_Deffn
-
-@pindex tmac.tty
-@Deffn{Request, nroff, }
+condition false) for @code{if}, @code{ie}, and @code{while}
+conditional requests.  This is the default if @code{gtroff}
+(@emph{not} @code{groff}) is started with the @option{-R} switch to
+avoid loading of the start-up files @file{troffrc} and
+@file{troffrc-end}.  Without @option{-R}, @code{gtroff} stays in troff
+mode if the output device is not a tty (e.g.@: `ps').
+@endDefreq
+
+@pindex tty.tmac
+@Defreq {nroff, }
 Make the @samp{n} built-in condition true (and the @samp{t} built-in
-condition false) for @code{if}, @code{ie}, and @code{while} conditional
-requests.  This is the default if @code{gtroff} uses a tty output
-device; the code for switching to nroff mode is in the file
-@file{tmac.tty} which will be loaded by the start-up file
-@code{troffrc}.
-@end_Deffn
-
-@xref{Conditionals and Loops}, for more details on built-in conditions.
-
+condition false) for @code{if}, @code{ie}, and @code{while}
+conditional requests.  This is the default if @code{gtroff} uses a tty
+output device; the code for switching to nroff mode is in the file
+@file{tty.tmac} which is loaded by the start-up file @code{troffrc}.
+@endDefreq
+
+@xref{Conditionals and Loops}, for more details on built-in
+conditions.
+
+@c XXX move the following to grotty section
+
+@pindex less
+@cindex Teletype
+@cindex ISO 6249 SGR
+@cindex terminal control sequences
+@cindex control sequences, for terminals
+For tty output devices, underlining is done by emitting sequences of
+@samp{_} and @samp{\b} (the backspace character) before the actual
+character.  Literally, this is printing an underline character, then
+moving back one character position, and printing the actual character
+at the same position as the underline character (similar to a
+typewriter).  Usually, a modern terminal can't interpret this (and the
+original Teletype machines for which this sequence was appropriate are
+no longer in use).  You need a pager program like @code{less} which
+translates this into ISO 6429 SGR sequences to control terminals.
 
 @c =====================================================================
 
-@node Line Layout, Page Layout, Troff and Nroff Mode, Programming Tutorial
+@node Line Layout, Page Layout, Troff and Nroff Mode, gtroff Reference
 @section Line Layout
 @cindex line layout
 @cindex layout, line
@@ -4858,8 +5260,7 @@ The following drawing shows the dimensions which @code{gtroff} uses for
 placing a line of output onto the page.  They are labeled with the
 request which manipulates each dimension.
 
-@example
-@group
+@Example
                 -->| in |<--
                    |<-----------ll------------>|
               +----+----+----------------------+----+
@@ -4867,8 +5268,7 @@ request which manipulates each dimension.
               +----+----+----------------------+----+
            -->| po |<--
               |<--------paper width---------------->|
-@end group
-@end example
+@endExample
 
 @noindent
 These dimensions are:
@@ -4886,7 +5286,7 @@ output, defining the @dfn{left margin}.
 @cindex indentation
 @cindex line indentation
 @dfn{Indentation} -- this is the distance from the left margin where
-text will be printed.
+text is printed.
 
 @item ll
 @cindex line length
@@ -4897,7 +5297,7 @@ margin.
 
 @c XXX improve example
 
-@example
+@Example
 .in +.5i
 .ll -.5i
 A bunch of really boring text which should
@@ -4905,32 +5305,29 @@ be indented from both margins.
 Replace me with a better (and more) example!
 .in -.5i
 .ll +.5i
-@end example
+@endExample
 
-@cindex troff mode
-@cindex mode, troff
-@cindex nroff mode
-@cindex mode, nroff
-@Deffn{Request, po, [@var{offset}]}
-@Deffnx{Request, po, +offset}
-@Deffnx{Request, po, -offset}
-Set horizontal page offset to @var{offset} (resp.@: increment or
-decrement the current value by @var{offset}).  Note that this request
-does not cause a break, so changing the page offset in the middle of
-text being filled may not yield the expected result.  The initial value
-is 1@dmn{i} if in troff mode, and 0 if in nroff mode (@pxref{Troff and
-Nroff Mode}); the default scaling indicator is@w{ }@code{m} (and not@w{
-}@code{v} as incorrectly documented in the original @acronym{UNIX} troff
-manual).
-
-@vindex .o
-The current page offset can be found in the built-in number register
+@pindex troffrc
+@Defreq {po, [@Var{offset}]}
+@Defreqx {po, @t{+}@Var{offset}}
+@Defreqx {po, @t{-}@Var{offset}}
+@Defregx {.o}
+Set horizontal page offset to @var{offset} (or increment or decrement
+the current value by @var{offset}).  Note that this request does not
+cause a break, so changing the page offset in the middle of text being
+filled may not yield the expected result.  The initial value is
+1@dmn{i}.  For tty output devices, it is set to 0 in the startup file
+@file{troffrc}; the default scaling indicator is@w{ }@code{m} (and
+not@w{ }@code{v} as incorrectly documented in the original
+@acronym{UNIX} troff manual).
+
+The current page offset can be found in the read-only number register
 @samp{.o}.
 
 If @code{po} is called without an argument, the page offset is reset to
 the previous value before the last call to @code{po}.
 
-@example
+@Example
 .po 3i
 \n[.o]
     @result{} 720
@@ -4940,13 +5337,14 @@ the previous value before the last call to @code{po}.
 .po
 \n[.o]
     @result{} 720
-@end example
-@end_Deffn
-
-@Deffn{Request, in, [@var{indent}]}
-@Deffnx{Request, in, +indent}
-@Deffnx{Request, in, -indent}
-Set indentation to @var{indent} (resp.@: increment or decrement the
+@endExample
+@endDefreq
+
+@Defreq {in, [@Var{indent}]}
+@Defreqx {in, @t{+}@Var{indent}}
+@Defreqx {in, @t{-}@Var{indent}}
+@Defregx {.i}
+Set indentation to @var{indent} (or increment or decrement the
 current value by @var{indent}).  This request causes a break.
 Initially, there is no indentation.
 
@@ -4961,23 +5359,23 @@ If a negative indentation value is specified (which is not allowed),
 indentation to zero.
 
 The effect of @code{in} is delayed until a partially collected line (if
-it exists) is output.
+it exists) is output.  A temporary indent value is reset to zero also.
 
-@vindex .i
 The current indentation (as set by @code{in}) can be found in the
-built-in number register @samp{.i}.
-@end_Deffn
+read-only number register @samp{.i}.
+@endDefreq
 
-@Deffn{Request, ti, offset}
-@Deffnx{Request, ti, +offset}
-@Deffnx{Request, ti, -offset}
+@Defreq {ti, offset}
+@Defreqx {ti, @t{+}@Var{offset}}
+@Defreqx {ti, @t{-}@Var{offset}}
+@Defregx {.in}
 Temporarily indent the next output line by @var{offset}.  If an
 increment or decrement value is specified, adjust the temporary
 indentation relative to the value set by the @code{in} request.
 
 This request causes a break; its value is associated with the current
-environment.  The default scaling indicator is@w{ }@code{m}.  A call of
-@code{ti} without an argument is ignored.
+environment.  The default scaling indicator is@w{ }@code{m}.  A call
+of @code{ti} without an argument is ignored.
 
 If the total indentation value is negative (which is not allowed),
 @code{gtroff} emits a warning of type @samp{range} and sets the
@@ -4988,23 +5386,24 @@ normal indentation, if @var{offset} is given as a relative value.
 The effect of @code{ti} is delayed until a partially collected line (if
 it exists) is output.
 
-@vindex .in
-The number register @code{.in} is the indentation that applies to the
-current output line.
+The read-only number register @code{.in} is the indentation that applies
+to the current output line.
 
 The difference between @code{.i} and @code{.in} is that the latter takes
 into account whether a partially collected line still uses the old
-indentation value resp.@: a temporary indentation value is active.
-@end_Deffn
-
-@Deffn{Request, ll, [@var{length}]}
-@Deffnx{Request, ll, +length}
-@Deffnx{Request, ll, -length}
-Set the line length to @var{length} (resp.@: increment or decrement the
+indentation value or a temporary indentation value is active.
+@endDefreq
+
+@Defreq {ll, [@Var{length}]}
+@Defreqx {ll, @t{+}@Var{length}}
+@Defreqx {ll, @t{-}@Var{length}}
+@Defregx {.l}
+@Defregx {.ll}
+Set the line length to @var{length} (or increment or decrement the
 current value by @var{length}).  Initially, the line length is set to
 6.5@dmn{i}.  The effect of @code{ll} is delayed until a partially
-collected line (if it exists) is output.  The default scaling indicator
-is@w{ }@code{m}.
+collected line (if it exists) is output.  The default scaling
+indicator is@w{ }@code{m}.
 
 If @code{ll} is called without an argument, the line length is reset to
 the previous value before the last call to @code{ll}.  If a negative
@@ -5013,22 +5412,20 @@ warning of type @samp{range} and sets the line length to zero.
 
 The line length is associated with the current environment.
 
-@vindex .l
-@vindex .ll
 @cindex current line length register
 The current line length (as set by @code{ll}) can be found in the
-built-in number register @code{.l}.  The number register @code{.ll} is
-the line length that applies to the current output line.
+read-only number register @samp{.l}.  The read-only number register
+@code{.ll} is the line length that applies to the current output line.
 
 Similar to @code{.i} and @code{.in}, the difference between @code{.l}
 and @code{.ll} is that the latter takes into account whether a partially
 collected line still uses the old line length value.
-@end_Deffn
+@endDefreq
 
 
 @c =====================================================================
 
-@node Page Layout, Page Control, Line Layout, Programming Tutorial
+@node Page Layout, Page Control, Line Layout, gtroff Reference
 @section Page Layout
 @cindex page layout
 @cindex layout, page
@@ -5038,16 +5435,16 @@ page layout.
 
 @cindex page length
 @cindex length of page
-@Deffn{Request, pl, [@var{length}]}
-@Deffnx{Request, pl, +length}
-@Deffnx{Request, pl, -length}
-Set the @dfn{page length} to @var{length} (resp.@: increment or
-decrement the current value by @var{length}).  This is the length of the
+@Defreq {pl, [@Var{length}]}
+@Defreqx {pl, @t{+}@Var{length}}
+@Defreqx {pl, @t{-}@Var{length}}
+@Defregx {.p}
+Set the @dfn{page length} to @var{length} (or increment or decrement
+the current value by @var{length}).  This is the length of the
 physical output page.  The default scaling indicator is@w{ }@code{v}.
 
-@vindex .p
 @cindex current page length register
-The current setting can be found in the built-in number register
+The current setting can be found in the read-only number register
 @samp{.p}.
 
 @cindex top margin
@@ -5055,13 +5452,16 @@ The current setting can be found in the built-in number register
 @cindex bottom margin
 @cindex margin, bottom
 Note that this only specifies the size of the page, not the top and
-bottom margins.  Those are not set by groff directly.  @xref{Traps}, for
-further information on how to do this.
+bottom margins.  Those are not set by @code{gtroff} directly.
+@xref{Traps}, for further information on how to do this.
 
 Negative @code{pl} values are possible also, but not very useful: No
 trap is sprung, and each line is output on a single page (thus
 suppressing all vertical spacing).
-@end_Deffn
+
+If no argument or an invalid argument is given, @code{pl} sets the page
+length to 11@dmn{i}.
+@endDefreq
 
 @cindex headers
 @cindex footers
@@ -5071,132 +5471,184 @@ and bottom titles (or headers and footers).
 
 @cindex title line
 @cindex three-part title
-@findex tl
-@vindex %
-The @code{tl} request will print a @dfn{title line}, which consists of
-three parts: a left justified portion, a centered portion and a right
-justified portion.  The argument to @code{tl} is specified as
-@code{'@var{left}'@var{center}'@var{right}'}.  The @samp{%} character is
-replaced with the current page number.  This character can be changed
-with the @code{pc} request (see below).
+@cindex page number character
+@Defreq {tl, @t{'}@Var{left}@t{'}@Var{center}@t{'}@Var{right}@t{'}}
+Print a @dfn{title line}.  It consists of three parts: a left
+justified portion, a centered portion, and a right justified portion.
+The argument separator @samp{'} can be replaced with any character not
+occurring in the title line.  The @samp{%} character is replaced with
+the current page number.  This character can be changed with the
+@code{pc} request (see below).
+
+Without argument, @code{tl} is ignored.
+
+Some notes:
+
+@itemize @bullet
+@item
+A title line is not restricted to the top or bottom of a page.
+
+@item
+@code{tl} prints the title line immediately, ignoring a partially filled
+line (which stays untouched).
+
+@item
+It is not an error to omit closing delimiters.  For example,
+@w{@samp{.tl /foo}} is equivalent to @w{@samp{.tl /foo///}}: It prints a
+title line with the left justified word @samp{foo}; the centered and
+right justfied parts are empty.
+
+@item
+Any modifications to the current environment within @code{tl} (e.g.@:
+changing the font or font size) are undone after processing @code{tl}.
+
+@item
+@code{tl} accepts the same parameter delimiting characters as the
+@code{\A} escape; see @ref{Escapes}.
+@end itemize
+@endDefreq
 
 @cindex length of title line
 @cindex title line, length
-@findex lt
-@vindex .lt
 @cindex current title line length register
-The title line is printed using its own line length, which is specified
-with the @code{lt} request.  The current setting of this is available in
-the @code{.lt} number register.
+@Defreq {lt, [@Var{length}]}
+@Defreqx {lt, @t{+}@Var{length}}
+@Defreqx {lt, @t{-}@Var{length}}
+@Defregx {.lt}
+The title line is printed using its own line length, which is
+specified (or incremented or decremented) with the @code{lt} request.
+Initially, the title line length is set to 6.5@dmn{i}.  If a negative
+line length is specified (which is not allowed), @code{gtroff} emits a
+warning of type @samp{range} and sets the title line length to zero.
+The default scaling indicator is@w{ }@code{m}.  If @code{lt} is called
+without an argument, the title length is reset to the previous value
+before the last call to @code{lt}.
+
+The current setting of this is available in the @code{.lt} read-only
+number register; it is associated with the current environment
+(@pxref{Environments}).
+
+@endDefreq
 
 @cindex page number
 @cindex number, page
-@findex pn
-The @code{pn} request will change the page number of the @emph{next}
-page.  The only argument is the page number.
+@Defreq {pn, page}
+@Defreqx {pn, @t{+}@Var{page}}
+@Defreqx {pn, @t{-}@Var{page}}
+@Defregx {.pn}
+Change (increase or decrease) the page number of the @emph{next} page.
+The only argument is the page number; the request is ignored without a
+parameter.
+
+The read-only number register @code{.pn} contains the number of the next
+page: either the value set by a @code{pn} request, or the number of the
+current page plus@w{ }1.
+@endDefreq
 
-@vindex %
-@vindex .pn
 @cindex current page number register
-The current page number is stored in the number register @code{%}.  The
-number register @code{.pn} contains the number of the next page: either
-the value set by a @code{pn} request, or the number of the current page
-plus@w{ }1.
+@Defreg {%}
+A read-write register holding the current page number.
+@endDefreg
 
 @cindex changing the page number character
 @cindex page number character, changing
-@findex pc
-The @code{pc} request will change the page number character (used by the
-@code{tl} request) to a different character.  With no argument, this
-mechanism is disabled.
+@vindex %
+@Defreq {pc, [@Var{char}]}
+Change the page number character (used by the @code{tl} request) to a
+different character.  With no argument, this mechanism is disabled.
+Note that this doesn't affect the number register @code{%}.
+@endDefreq
 
 @xref{Traps}.
 
 
 @c =====================================================================
 
-@node Page Control, Fonts, Page Layout, Programming Tutorial
+@node Page Control, Fonts, Page Layout, gtroff Reference
 @section Page Control
 @cindex page control
 @cindex control, page
 
-@findex bp
-@findex pn
+@rqindex pn
 @cindex new page
-To stop processing the current page, and move to the next page, invoke
-the @code{bp} request.  This request will also cause a break.  It can
-also take an argument of what the next page should be numbered.  The
-only difference between @code{bp} and @code{pn} is that @code{pn} does
-not cause a break or actually eject a page.
-
-@example
-.de newpage
-'bp
-'sp .5i
-.tl 'left top'center top'right top'
-'sp .3i
-..
-@end example
-
-@cindex orphan
-@findex ne
+@Defreq {bp, [@Var{page}]}
+@Defreqx {bp, @t{+}@Var{page}}
+@Defreqx {bp, @t{-}@Var{page}}
+Stop processing the current page and move to the next page.  This
+request causes a break.  It can also take an argument to set
+(increase, decrease) the page number of the next page.  The only
+difference between @code{bp} and @code{pn} is that @code{pn} does not
+cause a break or actually eject a page.
+
+@Example
+.de newpage                         \" define macro
+'bp                                 \" begin page
+'sp .5i                             \" vertical space
+.tl 'left top'center top'right top' \" title
+'sp .3i                             \" vertical space
+..                                  \" end macro
+@endExample
+
+@cindex top-level diversion
+@cindex diversion, top-level
+@code{bp} has no effect if not called within the top-level diversion
+(@pxref{Diversions}).
+@endDefreq
+
+@cindex orphan line
+@Defreq {ne, [@Var{space}]}
 It is often necessary to force a certain amount of space before a new
 page occurs.  This is most useful to make sure that there is not a
 single @dfn{orphan} line left at the bottom of a page.  The @code{ne}
-request will ensure that there is a certain distance, specified by the
-first argument, before the next page is triggered (see @ref{Traps}, for
-further information).  The default unit for @code{ne} is @code{v} and
-the default argument is@w{ }1@dmn{v}.
+request ensures that there is a certain distance, specified by the
+first argument, before the next page is triggered (see @ref{Traps},
+for further information).  The default unit for @code{ne} is @samp{v};
+the default value of @var{space} is@w{ }1@dmn{v} if no argument is
+given.
 
 For example, to make sure that no fewer than 2@w{ }lines get orphaned,
 do the following before each paragraph:
 
-@example
+@Example
 .ne 2
-.ti +5n
-text
-@end example
-
-@findex sv
-@findex os
-@findex ne
-@code{sv} is similar to the @code{ne} request; it reserves the specified
-amount of vertical space.  If the desired amount of space exists before
-the next trap (bottom page boundary), the space will be output
-immediately.  If there is not enough space, it is stored for later
-output via the @code{os} request.  The default argument is@w{ }1@dmn{v}
-and the default unit is @code{v}.
+text text text
+@endExample
+@endDefreq
+
+@rqindex os
+@rqindex ne
+@Defreq {sv, [@Var{space}]}
+@code{sv} is similar to the @code{ne} request; it reserves the
+specified amount of vertical space.  If the desired amount of space
+exists before the next trap (bottom page boundary), the space is
+output immediately (ignoring a partial filled line which stays
+untouched).  If there is not enough space, it is stored for later
+output via the @code{os} request.  The default value is@w{ }1@dmn{v}
+if no argument is given; the default unit is @samp{v}.
+@endDefreq
 
 
 @c =====================================================================
 
-@node Fonts, Sizes, Page Control, Programming Tutorial
+@node Fonts, Sizes, Page Control, gtroff Reference
 @section Fonts
 @cindex fonts
 
-@findex ft
-@findex \f
-@code{gtroff} has the ability to switch fonts at any point in the text.
-There are two ways to do this, via the @code{ft} request and the
-@code{\f} escape.
-
-Fonts are generally specified as upper-case strings, which are usually
-1@w{ }to 4 characters representing an abbreviation or acronym of the font
-name.
+@code{gtroff} can switch fonts at any point in the text.
 
-The basic set of fonts are @samp{R}, @samp{I}, @samp{B}, and @samp{BI}.
-These are Times Roman, Italic, Bold, and Bold Italic.  There is also at
-least one symbol font which contains various special symbols (Greek,
-mathematics).  Such symbols fonts cannot be used directly, but should be
-used via an escape.
+The basic set of fonts is @samp{R}, @samp{I}, @samp{B}, and @samp{BI}.
+These are Times Roman, Italic, Bold, and Bold Italic.  For non-tty
+devices, there is also at least one symbol font which contains various
+special symbols (Greek, mathematics).
 
 @menu
-* Changing Fonts::              
-* Font Families::               
-* Font Positions::              
-* Using Symbols::               
-* Artificial Fonts::            
-* Ligatures and Kerning::       
+* Changing Fonts::
+* Font Families::
+* Font Positions::
+* Using Symbols::
+* Special Fonts::
+* Artificial Fonts::
+* Ligatures and Kerning::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -5206,93 +5658,67 @@ used via an escape.
 @cindex changing fonts
 @cindex fonts, changing
 
-@findex ft
+@rqindex sty
+@rqindex fam
+@kindex styles
+@kindex family
+@pindex DESC
+@Defreq {ft, [@Var{font}]}
+@Defescx {\\f, , f, }
+@Defescx {\\f, @lparen{}, fn, }
+@Defescx {\\f, @lbrack{}, font, @rbrack}
+The @code{ft} request and the @code{\f} escape change the current font
+to @var{font} (one-character name @var{f}, two-character name
+@var{fn}).
+
+If @var{font} is a style name (as set with the @code{sty} request or
+with the @code{styles} command in the @file{DESC} file), use it within
+the current font family (as set with the @code{fam} request or with
+the @code{family} command in the @file{DESC} file).
+
 @cindex previous font
 @cindex font, previous
-Font changes can be done either with the @code{ft} request or the
-@code{\f} request.  With no arguments, it will switch to the previous
-font (also known as @samp{P}).
+With no argument or using @samp{P} as an argument, @code{.ft} switches
+to the previous font.  Use @code{\fP} or @code{\f[P]} to do this with
+the escape.
 
-@example
+Fonts are generally specified as upper-case strings, which are usually
+1@w{ }to 4 characters representing an abbreviation or acronym of the
+font name.  This is no limitation, just a convention.
+
+The example below produces two identical lines.
+
+@Example
 eggs, bacon,
 .ft B
 spam
 .ft
 and sausage.
-@end example
 
-@findex \f
-The @code{\f} escape is useful for changing fonts in the middle of
-words:
-
-@example
 eggs, bacon, \fBspam\fP and sausage.
-@end example
-
-@noindent
-Both of the above examples will produce the same output.  Note the usage
-of @samp{P} to indicate the previous font -- using @code{\f} it is not
-possible to omit this parameter.
-
-Sometimes, when putting letters of different fonts, more or less space at
-such boundaries are needed.  There are two escapes to help with this.
-
-@findex \/
-@cindex italic correction
-@cindex correction, italic
-The @code{\/} escape increases the width of the preceding character so
-that the spacing between that character and the following character will
-be correct if the following character is a Roman character.  For
-example, if an italic@w{ }f is immediately followed by a Roman right
-parenthesis, then in many fonts the top right portion of the f will
-overlap the top left of the right parenthesis.  It is a good idea to use
-this escape sequence whenever an italic character is immediately
-followed by a Roman character without any intervening space.  This small
-amount of space is also called @dfn{italic correction}.
-
-@c XXX example
-@c producing @i{f}), which is ugly.  Inserting \/ produces f) and avoids
-@c this problem.
-
-@findex \,
-@cindex left italic correction
-@cindex correction, left italic
-The @code{\,} escape modifies the spacing of the following character so
-that the spacing between that character and the preceding character will
-be correct if the preceding character is a Roman character.  It is a
-good idea to use this escape sequence whenever a Roman character is
-immediately followed by an italic character without any intervening
-space.  In analogy to above, this space could be called @dfn{left italic
-correction}, but this term isn't used widely.
-
-@c XXX example
-@c For example, inserting \, between the parenthesis and the f changes
-@c (f to (f.
-
-@findex ftr
-@findex ft
-@findex ul
-@findex bd
-@findex \f
-@findex cs
-@findex tkf
-@findex special
-@findex fspecial
-@findex fp
-@findex code
-The @code{ftr} request will translate fonts; its syntax is
-
-@example
-.ftr @var{F} @var{G}
-@end example
-
-@noindent
-which translates font@w{ }@var{F} to font@w{ }@var{G}.  Whenever a font
-named @var{F} is referred to in a @code{\f} escape sequence, or in the
-@code{ft}, @code{ul}, @code{bd}, @code{cs}, @code{tkf}, @code{special},
-@code{fspecial}, @code{fp}, or @code{code} requests, font@w{ }@var{G}
-will be used.  If @var{G} is missing, or equal to @var{F} then font@w{
-}@var{F} will not be translated.
+@endExample
+
+@xref{Font Positions}, for an alternative syntax.
+@endDefreq
+
+@rqindex ft
+@rqindex ul
+@rqindex bd
+@esindex \f
+@rqindex cs
+@rqindex tkf
+@rqindex special
+@rqindex fspecial
+@rqindex fp
+@rqindex code
+@Defreq {ftr, f [@Var{g}]}
+Translate font@w{ }@var{f} to font@w{ }@var{g}.  Whenever a font named
+@var{f} is referred to in a @code{\f} escape sequence, or in the
+@code{ft}, @code{ul}, @code{bd}, @code{cs}, @code{tkf},
+@code{special}, @code{fspecial}, @code{fp}, or @code{code} requests,
+font@w{ }@var{g} is used.  If @var{g} is missing or equal to @var{f}
+the translation is undone.
+@endDefreq
 
 @c ---------------------------------------------------------------------
 
@@ -5300,38 +5726,120 @@ will be used.  If @var{G} is missing, or equal to @var{F} then font@w{
 @subsection Font Families
 @cindex font families
 @cindex families, font
+@cindex font styles
+@cindex styles, font
 
 Due to the variety of fonts available, @code{gtroff} has added the
-concept of font families.  Each of these families has four styles
-(@samp{R}, @samp{I}, @samp{B} and @samp{BI}).
+concept of @dfn{font families} and @dfn{font styles}.  The fonts are
+specified as the concatenation of the font family and style.  Specifying
+a font without the family part causes @code{gtroff} to use that style of
+the current family.
 
-The fonts are specified as the concatenation of the font family and
-style.  Specifying a font without the family part will cause
-@code{gtroff} to use that style of the current family.  By default,
-@code{gtroff} uses the Times family.
+@cindex postscript fonts
+@cindex fonts, postscript
+Currently, only @sc{PostScript} fonts are set up to this mechanism.
+By default, @code{gtroff} uses the Times family with the four styles
+@samp{R}, @samp{I}, @samp{B}, and @samp{BI}.
 
 This way, it is possible to use the basic four fonts and to select a
-different font family on the command line.
+different font family on the command line (@pxref{Groff Options}).
 
-@findex fam
-@vindex .fam
-Font families can be switched with the @code{fam} request.  The current
-font family is available in the number register @code{.fam}.  This is a
-string-valued register.
+@Defreq {fam, [@Var{family}]}
+@Defregx {.fam}
+Switch font family to @var{family}.  If no argument is given, switch
+back to the previous font family.  The current font family is available
+in the read-only number register @samp{.fam} (this is a string-valued
+register); it is associated with the current environment.
 
-@example
-spam,
-.fam H
-spam,
-.ft B
+@Example
 spam,
-.fam T
+.fam H    \" helvetica family
+spam,     \" used font is family H + style R = HR
+.ft B     \" family H + style B = font HB
 spam,
-.ft AR
+.fam T    \" times family
+spam,     \" used font is family T + style B = TB
+.ft AR    \" font AR (not a style)
 baked beans,
-.ft R
+.ft R     \" family T + style R = font TR
 and spam.
-@end example
+@endExample
+@endDefreq
+
+@rqindex cs
+@rqindex bd
+@rqindex tkf
+@rqindex uf
+@rqindex fspecial
+@Defreq {sty, n style}
+Associate @var{style} with font position@w{ }@var{n}.  A font position
+can be associated either with a font or with a style.  The current
+font is the index of a font position and so is also either a font or a
+style.  When it is a style, the font that is actually used is the font
+the name of which is the concatenation of the name of the current
+family and the name of the current style.  For example, if the current
+font is@w{ }1 and font position@w{ }1 is associated with style@w{
+}@samp{R} and the current font family is@w{ }@samp{T}, then font
+@samp{TR} will be used.  If the current font is not a style, then the
+current family is ignored.  When the requests @code{cs}, @code{bd},
+@code{tkf}, @code{uf}, or @code{fspecial} are applied to a style, then
+they will instead be applied to the member of the current family
+corresponding to that style.
+
+@var{n} must be a non-negative integer value.
+
+@pindex DESC
+@kindex styles
+The default family can be set with the @option{-f} option
+(@pxref{Groff Options}).  The @code{styles} command in the @file{DESC}
+file controls which font positions (if any) are initially associated
+with styles rather than fonts.  For example, the default setting for
+@sc{PostScript} fonts
+
+@Example
+styles R I B BI
+@endExample
+
+@noindent
+is equivalent to
+
+@Example
+.sty 1 R
+.sty 2 I
+.sty 3 B
+.sty 4 BI
+@endExample
+
+@code{.fam} always checks whether the current font position is valid;
+this can give surprising results if the current font position is
+associated with a style.
+
+In the following example, we want to access the @sc{PostScript} font
+@code{FooBar} from the font family @code{Foo}:
+
+@Example
+.sty \n[.fp] Bar
+.fam Foo
+    @result{} warning: can't find font `FooR'
+@endExample
+
+@noindent
+The default font position at start-up is@w{ }1; for the
+@sc{PostScript} device, this is associated with style @samp{R}, so
+@code{gtroff} tries to open @code{FooR}.
+
+A solution to this problem is to use a dummy font like the following:
+
+@Example
+.fp 0 dummy TR    \" set up dummy font at position 0
+.sty \n[.fp] Bar  \" register style `Bar'
+.ft 0             \" switch to font at position 0
+.fam Foo          \" activate family `Foo'
+.ft Bar           \" switch to font `FooBar'
+@endExample
+
+@xref{Font Positions}.
+@endDefreq
 
 @c ---------------------------------------------------------------------
 
@@ -5340,132 +5848,199 @@ and spam.
 @cindex font positions
 @cindex positions, font
 
-For the sake of old phototypesetters and compatability with old versions
+For the sake of old phototypesetters and compatibility with old versions
 of @code{troff}, @code{gtroff} has the concept of font @dfn{positions},
-on which various fonts are mounted.  The last one or two are reserved
-for the symbol font(s).
-
-@findex fp
-New fonts can be mounted with the @code{fp} request.  These numeric
-positions can then be referred to with font changing commands.  When
-@code{gtroff} starts it is using font number one.
-
-@example
-.fp 1 H
-.fp 2 HI
-.fp 3 HB
-wink, wink,
-.ft 2
-nudge, nudge,
-.ft
-.ft 3
-say no more!
-.ft
-@end example
+on which various fonts are mounted.
 
-@noindent
-Note that after these font changes have taken place, the original font
-is restored.
+@Defreq {fp, pos font [@Var{external-name}]}
+@Defregx {.f}
+@Defregx {.fp}
+Mount font @var{font} at position @var{pos} (which must be a
+non-negative integer).  This numeric position can then be referred to
+with font changing commands.  When @code{gtroff} starts it is using
+font position@w{ }1 (which must exist; position@w{ }0 is unused
+usually at start-up).
 
-@vindex .f
 @cindex current font position register
-The current font in use, as a font position, is available in number
-register @code{.f}.  This can be useful to remember the current font,
-for later recall.
+The current font in use, as a font position, is available in the
+read-only number register @samp{.f}.  This can be useful to remember the
+current font for later recall.  It is associated with the current
+environment (@pxref{Environments}).
 
-@example
-.nr save-font \n(.f
-... lots 'o text ...
+@Example
+.nr save-font \n[.f]
+.ft B
+... text text text ...
 .ft \n[save-font]
-@end example
+@endExample
 
-@vindex .fp
 @cindex next free font position register
-The number of the next free font position is available in the number
-register @code{.fp}.  This is useful when mounting a new font, like so:
+The number of the next free font position is available in the read-only
+number register @samp{.fp}.  This is useful when mounting a new font,
+like so:
 
-@example
+@Example
 .fp \n[.fp] NEATOFONT
-@end example
+@endExample
 
 @pindex DESC@r{, and font mounting}
 Fonts not listed in the @file{DESC} file are automatically mounted on
-the next available font position when they are referenced.  If a font is
-to be mounted explicitly with the @code{fp} request on an unused font
-position, it should be mounted on the first unused font position, which
-can be found in the @code{.fp} register.  Although @code{gtroff} does
-not enforce this strictly, it will not allow a font to be mounted at a
-position whose number is much greater than that of any currently used
-position.
+the next available font position when they are referenced.  If a font
+is to be mounted explicitly with the @code{fp} request on an unused
+font position, it should be mounted on the first unused font position,
+which can be found in the @code{.fp} register.  Although @code{gtroff}
+does not enforce this strictly, it is not allowed to mount a font at a
+position whose number is much greater (approx.@: 1000 positions) than
+that of any currently used position.
 
-@findex fp
 The @code{fp} request has an optional third argument.  This argument
 gives the external name of the font, which is used for finding the font
 description file.  The second argument gives the internal name of the
 font which is used to refer to the font in @code{gtroff} after it has
-been mounted.  If there is no third argument then the internal name will
-be used as the external name.  This feature make it possible to use
+been mounted.  If there is no third argument then the internal name is
+used as the external name.  This feature makes it possible to use
 fonts with long names in compatibility mode.
+@endDefreq
+
+Both the @code{ft} request and the @code{\f} escape have alternative
+syntax forms to access font positions.
+
+@rqindex sty
+@rqindex fam
+@kindex styles
+@kindex family
+@pindex DESC
+@Defreq {ft, nnn}
+@Defescx {\\f, , n, }
+@Defescx {\\f, @lparen{}, nn, }
+@Defescx {\\f, @lbrack{}, nnn, @rbrack}
+Change the current font position to @var{nnn} (one-digit position
+@var{n}, two-digit position @var{nn}), which must be a non-negative
+integer.
+
+If @var{nnn} is associated with a style (as set with the @code{sty}
+request or with the @code{styles} command in the @file{DESC} file), use
+it within the current font family (as set with the @code{fam} request or
+with the @code{family} command in the @file{DESC} file).
+
+@Example
+this is font 1
+.ft 2
+this is font 2
+.ft                   \" switch back to font 1
+.ft 3
+this is font 3
+.ft
+this is font 1 again
+@endExample
+
+@xref{Changing Fonts}, for the standard syntax form.
+@endDefreq
 
 @c ---------------------------------------------------------------------
 
-@node Using Symbols, Artificial Fonts, Font Positions, Fonts
+@node Using Symbols, Special Fonts, Font Positions, Fonts
 @subsection Using Symbols
 @cindex using symbols
 @cindex symbols, using
 
-@findex \(
-@findex \[
-Symbols can be inserted by using a special escape sequence.  This escape
-is simply the escape character (usually a backslash) followed by an
-identifier.  The symbol identifiers have to be two or more characters,
-since single characters conflict with all the other escapes.  The
-identifier can be either preceded by a parenthesis if it is two
-characters long, or surrounded by square brackets.  So, the symbol for
-the mathematical Greek letter `pi' can be produced either by @code{\(*p}
-or @code{\[*p]}.
+@cindex glyph
+@cindex character
+@cindex ligature
+A @dfn{glyph} is a graphical representation of a @dfn{character}.
+While a character is an abstract entity containing semantic
+information, a glyph is something which can be actually seen on screen
+or paper.  It is possible that a character has multiple glyph
+representation forms (for example, the character `A' can be either
+written in a roman or an italic font, yielding two different glyphs);
+sometimes more than one character maps to a single glyph (this is a
+@dfn{ligature} -- the most common is `fi').
 
-@example
-area = \(*p\fIr\fP\u2\d
-@end example
+@c XXX
 
-@findex \C
-The escape @code{\C'@var{xxx}'} will typeset the character named
-@var{xxx}.  Normally it is more convenient to use @code{\[@var{xxx}]}.
-But @code{\C} has the advantage that it is compatible with recent
-versions of @code{ditroff} and is available in compatibility mode.
-
-@findex \N
-@findex char
-The escape @code{\N'@var{n}'} will typeset the character with code@w{
-}@var{n} in the current font.  @var{n} can be any integer.  Most devices
-only have characters with codes between 0 and@w{ }255.  If the current
-font does not contain a character with that code, special fonts will
-@emph{not} be searched.  The @code{\N} escape sequence can be
-conveniently used on conjunction with the @code{char} request:
+Please note that currently the distinction between glyphs and
+characters in this reference is not clearly carried out.  This will be
+improved eventually in the next revision.
 
-@example
-.char \[phone] \f(ZD\N'37'
-@end example
+@cindex symbol
+@cindex special fonts
+@kindex fonts
+@pindex DESC
+@rqindex fspecial
+A @dfn{symbol} is simply a named glyph.  Within @code{gtroff}, all
+glyph names of a particular font are defined in its font file.  If the
+user requests a glyph not available in this font, @code{gtroff} looks
+up an ordered list of @dfn{special fonts}.  By default, the
+@sc{PostScript} output device supports the two special fonts @samp{SS}
+(slanted symbols) and @samp{S} (symbols) (the former is looked up
+before the latter).  Other output devices use different names for
+special fonts.  Fonts mounted with the @code{fonts} keyword in the
+@file{DESC} file are globally available.  To install additional
+special fonts locally (i.e.@: for a particular font), use the
+@code{fspecial} request.
+
+@xref{Font Files}, and @ref{Special Fonts}, for more details.
+
+@Defesc {\\, @lparen{}, nm, }
+@Defescx {\\, @lbrack{}, name, @rbrack}
+Insert a symbol @var{name} (two-character name @var{nm}).  There is no
+special syntax for one-character names -- the natural form
+@samp{\@var{n}} would collide with escapes.
+
+If @var{name} is undefined, a warning of type @samp{char} is generated,
+and the escape is ignored.  @xref{Debugging}, for information about
+warnings.
+
+The list of available symbols is device dependent; see @ref{Glyph Name
+Index} for some of them discussed in this reference.
+
+@c XXX list of common symbols
+@endDefesc
+
+@Defesc {\\C, ', xxx, '}
+Typeset the character named @var{xxx}.  Normally it is more convenient
+to use @code{\[@var{xxx}]}, but @code{\C} has the advantage that it is
+compatible with newer versions of @code{ditroff} and is available in
+compatibility mode.
+@endDefesc
+
+@rqindex char
+@cindex unicode
+@Defesc {\\N, ', n, '}
+Typeset the character with code@w{ }@var{n} in the current font (this
+is @strong{not} the input character code).  @var{n} can be any
+integer.  Most devices only have characters with codes between 0
+and@w{ }255; the Unicode output device uses codes in the range
+0--65535.  If the current font does not contain a character with that
+code, special fonts are @emph{not} searched.  The @code{\N} escape
+sequence can be conveniently used in conjunction with the @code{char}
+request:
+
+@Example
+.char \[phone] \f[ZD]\N'37'
+@endExample
 
 @noindent
 @pindex DESC
 @cindex unnamed characters
 @cindex characters, unnamed
 The code of each character is given in the fourth column in the font
-description file after the charset command.  It is possible to include
-unnamed characters in the font description file by using a name of
-@samp{---}; the @code{\N} escape sequence is the only way to use these.
+description file after the @code{charset} command.  It is possible to
+include unnamed characters in the font description file by using a
+name of @samp{---}; the @code{\N} escape sequence is the only way to
+use these.
+@endDefesc
 
 @c XXX should be `glyph', not `character'
 
-@findex cflags
 @cindex character properties
 @cindex properties of characters
+@Defreq {cflags, n c1 c2 @dots{}}
 Each character has certain properties associated with it.  These
 properties can be modified with the @code{cflags} request.  The first
-argument is the the sum of the desired flags and the remaining arguments
-are the characters to have those properties.
+argument is the the sum of the desired flags and the remaining
+arguments are the characters to have those properties.  It is possible
+to omit the spaces between the characters.
 
 @table @code
 @item 1
@@ -5511,98 +6086,185 @@ this property)
 @glindex dg
 @glindex rq
 an end of sentence character followed by any number of characters with
-this property will be treated as the end of a sentence if followed by a
-newline or two spaces; in other words the character is @dfn{transparent}
-for the purposes of end of sentence recognition -- this is the same as
-having a zero space factor in @TeX{} (initially characters
-@samp{"')]*\(dg\(rq} have this property).
+this property is treated as the end of a sentence if followed by a
+newline or two spaces; in other words the character is
+@dfn{transparent} for the purposes of end of sentence recognition --
+this is the same as having a zero space factor in @TeX{} (initially
+characters @samp{"')]*\(dg\(rq} have this property).
 @end table
+@endDefreq
 
-@findex char
 @cindex defining characters
 @cindex characters, defining
 @cindex creating new characters
-New characters can be created with the @code{char} request.  It is
-called as
-
-@example
-.char @var{c} @var{string}
-@end example
-
-@findex tr
-@findex lc
-@findex \l
-@findex \L
-@findex hcode
-@noindent
-This defines character@w{ }@var{c} to be @var{string}.  Every time
-character@w{ }@var{c} needs to be printed, @var{string} will be
-processed in a temporary environment and the result will be wrapped up
-into a single object.  Compatibility mode will be turned off and the
-escape character will be set to @samp{\} while @var{string} is being
-processed.  Any emboldening, constant spacing or track kerning will be
+@cindex escape character
+@cindex character, escape
+@rqindex tr
+@rqindex cp
+@rqindex rc
+@rqindex lc
+@esindex \l
+@esindex \L
+@esindex \&
+@esindex \e
+@rqindex hcode
+@Defreq {char, c [@Var{string}]}
+Define a new character@w{ }@var{c} to be @var{string} (which can be
+empty).  Every time character@w{ }@var{c} needs to be printed,
+@var{string} is processed in a temporary environment and the result is
+wrapped up into a single object.  Compatibility mode is turned off and
+the escape character is set to @samp{\} while @var{string} is being
+processed.  Any emboldening, constant spacing or track kerning is
 applied to this object rather than to individual characters in
-@var{string}.  A character defined by this request can be used just like
-a normal character provided by the output device.  In particular other
-characters can be translated to it with the @code{tr} request; it can be
-made the leader character by the @code{lc} request; repeated patterns
-can be drawn with the character using the @code{\l} and @code{\L} escape
-sequences; words containing the character can be hyphenated correctly,
-if the @code{hcode} request is used to give the character a hyphenation
-code.  There is a special anti-recursion feature: use of character
-within the character's definition will be handled like normal characters
-not defined with @code{char}.
-
-@findex rchar
+@var{string}.  A character defined by this request can be used just
+like a normal character provided by the output device.  In particular,
+other characters can be translated to it with the @code{tr} request;
+it can be made the leader character by the @code{lc} request; repeated
+patterns can be drawn with the character using the @code{\l} and
+@code{\L} escape sequences; words containing the character can be
+hyphenated correctly, if the @code{hcode} request is used to give the
+character a hyphenation code.  There is a special anti-recursion
+feature: Use of character within the character's definition is handled
+like normal characters not defined with @code{char}.
+@endDefreq
+
 @cindex removing character definition
 @cindex character, removing definition
-A character definition can be removed with the @code{rchar} request.
-Its arguments are the characters to be removed.  This undoes the effect
-of a @code{char} request.
+@Defreq {rchar, c1 c2 @dots{}}
+Remove the definitions of characters @var{c1}, @var{c2},@w{
+}@enddots{} This undoes the effect of a @code{char} request.
+
+It is possible to omit the whitespace between arguments.
+@endDefreq
 
 @xref{Special Characters}.
 
 @c ---------------------------------------------------------------------
 
-@node Artificial Fonts, Ligatures and Kerning, Using Symbols, Fonts
+@node Special Fonts, Artificial Fonts, Using Symbols, Fonts
+@subsection Special Fonts
+@cindex special fonts
+@cindex fonts, special
+
+@c XXX
+
+To be written.
+
+@c ---------------------------------------------------------------------
+
+@node Artificial Fonts, Ligatures and Kerning, Special Fonts, Fonts
 @subsection Artificial Fonts
 @cindex artificial fonts
 @cindex fonts, artificial
 
 There are a number of requests for artificially creating fonts.  These
-are largely vestigial remains from the days when output devices did not
-have a wide variety of fonts, and when @code{nroff} and @code{troff}
-were separate programs.  These are no longer necessary in GNU
-@code{troff}.
+are largely vestiges of the days when output devices did not have a
+wide variety of fonts, and when @code{nroff} and @code{troff} were
+separate programs.  These are no longer necessary in GNU
+@code{troff}.  Nevertheless, they are supported.
 
-@findex ul
 @cindex underlining
-The @code{ul} request will print subsequent lines in italics on a device
-capable of it, or underline the text on a character output device.  The
-single argument is the number of lines to be ``underlined,'' with no
-argument, the next line will be underlined.
+@Defreq {ul, [@Var{lines}]}
+The @code{ul} request normally underlines subsequent lines if a tty
+output device is used.  Otherwise, the lines are printed in italics
+(only the term `underlined' is used in the following).  The single
+argument is the number of input lines to be underlined; with no
+argument, the next line is underlined.  If @var{lines} is zero or
+negative, stop the effects of @code{ul} (if it was active).  Requests
+and empty lines do not count for computing the number of underlined
+input lines, even if they produce some output like @code{tl}.  Lines
+inserted by macros (e.g.@: invoked by a trap) do count.
+
+At the beginning of @code{ul}, the current font is stored and the
+underline font is activated.  Within the span of a @code{ul} request,
+it is possible to change fonts, but after the last line affected by
+@code{ul} the saved font is restored.
+
+@cindex underline font
+@cindex font, for underlining
+@rqindex uf
+This command is associated with the current environment.  The
+underline font can be changed with the @code{uf} request.
+
+@c XXX @xref should be changed to grotty
+
+@xref{Troff and Nroff Mode}, for a discussion how underlining is
+implemented in for tty output devices, and which problems can arise.
+
+The @code{ul} request does not underline spaces.
+@endDefreq
 
-@findex cu
 @cindex continuous underlining
 @cindex underlining, continuous
-The @code{cu} request is similar to @code{ul} ...
+@Defreq {cu, [@Var{lines}]}
+The @code{cu} request is similar to @code{ul} but underlines spaces as
+well (if a tty output device is used).
+@endDefreq
 
-@c XXX more info
-
-@findex uf
 @cindex underline font
 @cindex font for underlining
-The @code{uf} request will set the underline font used by @code{ul} and
-@code{cu}.
+@rqindex ul
+@rqindex cu
+@Defreq {uf, font}
+Set the underline font (globally) used by @code{ul} and @code{cu}.  By
+default, this is the font at position@w{ }2.  @var{font} can be either
+a non-negative font position or the name of a font.
+@endDefreq
 
-@findex bd
 @cindex imitating bold face
 @cindex bold face, imitating
-The @code{bd} request artificially creates a bold font by printing each
-character twice, slightly offset.  The first argument specifies the font
-to embolden, and the second is the number of basic units, minus one, by
-which the two characters will be offset.  If the second argument is
-missing, emboldening will be turned off.
+@Defreq {bd, font [@Var{offset}]}
+@Defreqx {bd, font1 font2 [@Var{offset}]}
+@Defregx {.b}
+Artificially create a bold font by printing each character twice,
+slightly offset.
+
+Two syntax forms are available.
+
+@itemize @bullet
+@item
+Imitate a bold font unconditionally.  The first argument specifies the
+font to embolden, and the second is the number of basic units, minus
+one, by which the two characters is offset.  If the second argument is
+missing, emboldening is turned off.
+
+@var{font} can be either a non-negative font position or the name of a
+font.
+
+@var{offset} is available in the @code{.b} read-only register if a
+special font is active; in the @code{bd} request, its default unit is
+@samp{u}.
+
+@rqindex fspecial
+@kindex special
+@cindex embolding of special fonts
+@cindex special fonts, emboldening
+@item
+Imitate a bold form conditionally.  Embolden @var{font1} by
+@var{offset} only if font @var{font2} is the current font.  This
+command can be issued repeatedly to set up different emboldening
+values for different current fonts.  If the second argument is
+missing, emboldening is turned off for this particular current font.
+
+This affects special fonts only (either set up with the @code{special}
+command in font files or with the @code{fspecial} request).
+@end itemize
+@endDefreq
+
+@cindex constant character space mode
+@cindex mode for constant character space
+@cindex character, constant space
+@rqindex ps
+@Defreq {cs, font [@Var{width} [@Var{em-size}]]}
+Switch to and from constant character space mode.  If activated, the
+width of every character is @math{@var{width}/36} ems.  The em size is
+given absolutely by @var{em-size}; if this argument is missing, the em
+value is taken from the current font size (as set with the @code{ps}
+request) when the font is effectively in use.  Without second and
+third argument, constant character space mode is deactivated.
+
+Default unit for @var{em-size} is @samp{z}; @var{width} is an integer.
+@endDefreq
 
 @c ---------------------------------------------------------------------
 
@@ -5611,68 +6273,192 @@ missing, emboldening will be turned off.
 @cindex ligatures and kerning
 @cindex kerning and ligatures
 
-@c XXX What are ligatures?
+Ligatures are groups of characters that are run together.  For
+example, the letters `f' and `i' can form a ligature `fi' as in the
+word `file'.  This produces a cleaner look (albeit subtle) to the
+printed output.  Usually, ligatures are not available in fonts for tty
+output devices.
 
-@c XXX more info
+Most @sc{PostScript} fonts support the fi and fl ligatures.  The C/A/T
+typesetter that was the target of AT&T @code{troff} also supported
+`ff', `ffi', and `ffl' ligatures.  Advanced typesetters or `expert'
+fonts may include ligatures for `ft' and `ct', although GNU
+@code{troff} does not support these (yet).
 
-@findex lg
-@vindex .lg
 @cindex ligatures enabled register
+@Defreq {lg, [@Var{flag}]}
+@Defregx {.lg}
 The ligature mechanism can be switched on or off with the @code{lg}
-request; if the parameter is non-zero or missing, ligatures are enabled,
-otherwise disabled.  Default is on.  The current ligature mode can be
-found in the number register @code{.lg} (set to@w{ }1 if ligatures are
-enabled, 0@w{ }otherwise).
-
-@c XXX What is kerning?
+request; if the parameter is non-zero or missing, ligatures are
+enabled, otherwise disabled.  Default is on.  The current ligature
+mode can be found in the read-only number register @code{.lg} (set to
+1 or@w{ }2 if ligatures are enabled, 0@w{ }otherwise).
+
+Setting the ligature mode to@w{ }2 enables the two-character ligatures
+(fi, fl, and ff) and disables the three-character ligatures (ffi and
+ffl).
+@endDefreq
+
+@dfn{Pairwise kerning} is another subtle typesetting mechanism that
+modifies the distance between a character pair to improve readability.
+In most cases (but not always) the distance is decreased.
+@ifnotinfo
+For example, compare the combination of the letters `V' and `A'.  With
+kerning, `VA' is printed.  Without kerning it appears as `V@w{}A'.
+@end ifnotinfo
+Typewriter-like fonts and fonts for terminals where all characters
+have the same width don't use kerning.
 
-@c XXX more info
+@cindex kerning enabled register
+@Defreq {kern, [@Var{flag}]}
+@Defregx {.kern}
+Kerning can be activated with the @code{kern} request.  If the
+parameter is non-zero or missing, enable pairwise kerning, otherwise
+disable it.  The read-only number register @code{.kern} is set to@w{
+}1 if pairwise kerning is enabled, 0@w{ }otherwise.
 
 @cindex zero width space character
 @cindex character, zero width space
 @cindex space character, zero width
 If the font description file contains pairwise kerning information,
-characters from that font will be kerned.  Kerning between two
-characters can be inhibited by placing @code{\&} between them.
+characters from that font are kerned.  Kerning between two characters
+can be inhibited by placing @code{\&} between them: @samp{V\&A}.
 
-@findex kern
-@vindex .kern
-@cindex kerning enabled register
-Kerning can be activated with the @code{kern} request.  If the parameter
-is non-zero or missing, enable pairwise kerning, otherwise disable it.
-The number register @code{.kern} is set to@w{ }1 if pairwise kerning is
-enabled, 0@w{ }otherwise.
+@xref{Font File Format}.
+@endDefreq
 
-@findex tkf
 @cindex track kerning
 @cindex kerning, track
+@dfn{Track kerning} expands or reduces the space between characters.
+This can be handy, for example, if you need to squeeze a long word
+onto a single line or spread some text to fill a narrow column.  It
+must be used with great care since it is usually considered bad
+typography if the reader notices the effect.
 
-@c XXX What is track kerning?
+@Defreq {tkf, f s1 n1 s2 n2}
+Enable track kerning for font@w{ }@var{f}.  If the current font is@w{
+}@var{f} the width of every character is increased by an amount
+between @var{n1} and @var{n2} (@var{n1}, @var{n2} can be negative); if
+the current point size is less than or equal to @var{s1} the width is
+increased by @var{n1}; if it is greater than or equal to @var{s2} the
+width is increased by @var{n2}; if the point size is greater than or
+equal to @var{s1} and less than or equal to @var{s2} the increase in
+width is a linear function of the point size.
+
+The default unit is @samp{z} for @var{s1} and @var{s2}, @samp{p} for
+@var{n1} and @var{n2}.
+@endDefreq
+
+Sometimes, when typesetting letters of different fonts, more or less
+space at such boundaries are needed.  There are two escapes to help
+with this.
 
-@c XXX more info
+@cindex italic correction
+@cindex correction, italic
+@cindex correction between italic and roman character
+@cindex roman character, correction after italic character
+@cindex italic character, correction before roman character
+@Defesc {\\/, , , }
+Increase the width of the preceding character so that the spacing
+between that character and the following character is correct if the
+following character is a roman character.  For example, if an
+italic@w{ }@code{f} is immediately followed by a roman right
+parenthesis, then in many fonts the top right portion of the @code{f}
+overlaps the top left of the right parenthesis.  Use this escape
+sequence whenever an italic character is immediately followed by a
+roman character without any intervening space.  This small amount of
+space is also called @dfn{italic correction}.
 
-Track kerning must be used with great care since it is usually
-considered bad typography if the reader notices the effect.  The syntax
-of the @code{tkf} request is like this:
+@iftex
+@example
+@group
+\f[I]f\f[R])
+    @result{} {@it f}@r{)}
+\f[I]f\/\f[R])
+    @result{} @i{f}@r{)}
+@end group
+@end example
+@end iftex
+@endDefesc
 
+@cindex left italic correction
+@cindex correction, left italic
+@cindex roman character, correction before italic character
+@cindex italic character, correction after roman character
+@Defesc {\\\,, , , }
+Modify the spacing of the following character so that the spacing
+between that character and the preceding character is correct if the
+preceding character is a roman character.  Use this escape sequence
+whenever a roman character is immediately followed by an italic
+character without any intervening space.  In analogy to above, this
+space could be called @dfn{left italic correction}, but this term
+isn't used widely.
+
+@iftex
 @example
-.tkf @var{f} @var{s1} @var{n1} @var{s2} @var{n2}
+@group
+q\f[I]f
+    @result{} @r{q}@i{f}
+q\,\f[I]f
+    @result{} @r{q}@math{@ptexcomma}@i{f}
+@end group
 @end example
+@end iftex
+@endDefesc
 
-@noindent
-Enable track kerning for font@w{ }@var{f}.  If the current font is@w{
-}@var{f} the width of every character will be increased by an amount
-between @var{n1} and @var{n2}; if the current point size is less than or
-equal to @var{s1} the width will be increased by @var{n1}; if it is
-greater than or equal to @var{s2} the width will be increased by
-@var{n2}; if the point size is greater than or equal to @var{s1} and
-less than or equal to @var{s2} the increase in width is a linear
-function of the point size.
+@Defesc {\\&, , , }
+Insert a zero-width character, which is invisible.  Its intended use
+is to stop interaction of a character with its surrounding.
+
+@itemize @bullet
+@item
+It prevents the insertion of extra space after an end of sentence
+character.
+
+@Example
+Test.
+Test.
+    @result{} Test.  Test.
+Test.\&
+Test.
+    @result{} Test. Test.
+@endExample
+
+@item
+It prevents interpretation of a control character at the beginning of
+an input line.
+
+@Example
+.Test
+    @result{} warning: `Test' not defined
+\&.Test
+    @result{} .Test
+@endExample
+
+@item
+It prevents kerning between two characters.
+
+@ifnotinfo
+@example
+@group
+VA
+    @result{} @r{VA}
+V\&A
+    @result{} @r{V@w{}A}
+@end group
+@end example
+@end ifnotinfo
+
+@item
+It is needed to map an arbitrary character to nothing in the @code{tr}
+request (@pxref{Character Translations}).
+@end itemize
+@endDefesc
 
 
 @c =====================================================================
 
-@node Sizes, Strings, Fonts, Programming Tutorial
+@node Sizes, Strings, Fonts, gtroff Reference
 @section Sizes
 @cindex sizes
 
@@ -5681,23 +6467,29 @@ function of the point size.
 @cindex size of type
 @cindex vertical spacing
 @cindex spacing, vertical
-@code{gtroff} uses two dimensions with each line of text, type size and
-vertical spacing.  The @dfn{type size} is the height from the text
-@dfn{baseline} to the top of the tallest character (descenders may drop
-below this baseline).  @dfn{Vertical spacing} is the amount of space
-@code{gtroff} allows for a line of text; normally, this is about 20%@w{
-}larger than the current type size.  Ratios smaller than this can result
-in hard-to-read text; larger that this, it will spread the text out more
-vertically (useful for term papers).  By default, @code{gtroff} uses
-10@w{ }point type on 12@w{ }point spacing.
+@code{gtroff} uses two dimensions with each line of text, type size
+and vertical spacing.  The @dfn{type size} is approximately the height
+of the tallest character.@footnote{This is usually the parenthesis.
+Note that in most cases the real dimensions of the glyphs in a font
+are @emph{not} related to its type size!  For example, the standard
+@sc{PostScript} font families `Times Roman', `Helvetica', and
+`Courier' can't be used together at 10@dmn{pt}; to get acceptable
+output, the size of `Helvetica' has to be reduced by one point, and
+the size of `Courier' must be increased by one point.}  @dfn{Vertical
+spacing} is the amount of space @code{gtroff} allows for a line of
+text; normally, this is about 20%@w{ }larger than the current type
+size.  Ratios smaller than this can result in hard-to-read text;
+larger than this, it spreads the text out more vertically (useful for
+term papers).  By default, @code{gtroff} uses 10@w{ }point type on
+12@w{ }point spacing.
 
 @cindex leading
 The difference between type size and vertical spacing is known, by
 typesetters, as @dfn{leading}.
 
 @menu
-* Changing Type Sizes::         
-* Fractional Type Sizes::       
+* Changing Type Sizes::
+* Fractional Type Sizes::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -5707,32 +6499,34 @@ typesetters, as @dfn{leading}.
 @cindex changing type sizes
 @cindex type sizes, changing
 
-@findex ps
-@findex vs
-@findex \s
-@vindex .s
-@vindex .v
-@cindex current type size register
-@cindex current vertical spacing register
-Using the @code{ps} request and the @code{\s} escape the type size can
-be changed.  The @code{vs} request will change the vertical spacing.
-The default unit for the @code{ps} and @code{vs} requests are points.
-The number registers @code{.s} and @code{.v} contain the current type
-size and vertical spacing.
+@Defreq {ps, [@Var{size}]}
+@Defreqx {ps, @t{+}@Var{size}}
+@Defreqx {ps, @t{-}@Var{size}}
+@Defescx {\\s, , size, }
+@Defregx {.s}
+Use the @code{ps} request or the @code{\s} escape to change (increase,
+decrease) the type size (in points).  Specify @var{size} as either an
+absolute point size, or as a relative change from the current size.
+The size@w{ }0, or no argument, goes back to the previous size.
 
-These requests take parameters in units of points.  It is possible to
-specify sizes as an absolute size, or as a relative change from the
-current size.  The size@w{ }0 means go back to the previous size.  With
-no argument it will also revert to the previous size.
+Default unit of @code{size} is @samp{z}.  If @code{size} is zero or
+negative, it is set to 1@dmn{u}.
 
-@example
+The read-only number register @code{.s} returns the point size in
+points as a decimal fraction.  This is a string.  To get the point
+size in scaled points, use the @code{.ps} register instead.
+
+@code{.s} is associated with the current environment
+(@pxref{Environments}).
+
+@Example
 snap, snap,
 .ps +2
 grin, grin,
 .ps +2
 wink, wink, \s+2nudge, nudge,\s+8 say no more!
 .ps 10
-@end example
+@endExample
 
 The @code{\s} escape may be called in a variety of ways.  Much like
 other escapes there must be a way to determine where the argument ends
@@ -5740,38 +6534,61 @@ and the text begins.  Any of the following forms are valid:
 
 @table @code
 @item \s@var{n}
-Set the point size to @var{n}@w{ }points.  @var{n}@w{ }must be either 0
-or in the range 4 to@w{ }39.
+Set the point size to @var{n}@w{ }points.  @var{n}@w{ }must be either
+0 or in the range 4 to@w{ }39.
 
 @item \s+@var{n}
 @itemx \s-@var{n}
-Increase resp.@: decrease the point size by @var{n}@w{ }points.
-@var{n}@w{ }must be exactly one digit.
+Increase or decrease the point size by @var{n}@w{ }points.  @var{n}@w{
+}must be exactly one digit.
 
 @item \s(@var{nn}
-Set the point size to @var{nn}@w{ }points.  @var{nn} must be exactly two
-digits.
+Set the point size to @var{nn}@w{ }points.  @var{nn} must be exactly
+two digits.
 
 @item \s+(@var{nn}
 @itemx \s-(@var{nn}
 @itemx \s(+@var{nn}
 @itemx \s(-@var{nn}
-Increase resp.@: decrease the point size by @var{nn}@w{ }points.
-@var{nn} must be exactly two digits.
+Increase or decrease the point size by @var{nn}@w{ }points.  @var{nn}
+must be exactly two digits.
 @end table
 
-@xref{Fractional Type Sizes}, for yet another syntactical form of using
-the @code{\s} escape.
+@xref{Fractional Type Sizes}, for yet another syntactical form of
+using the @code{\s} escape.
 
 Some devices may only have certain permissible sizes, in which case
-@code{gtroff} will round to the nearest permissible size.
+@code{gtroff} rounds to the nearest permissible size.
+@endDefreq
+
+@cindex current type size register
+@cindex current vertical spacing register
+@Defreq {vs, [@Var{space}]}
+@Defreqx {vs, @t{+}@Var{space}}
+@Defreqx {vs, @t{-}@Var{space}}
+@Defregx {.v}
+Change (increase, decrease) the vertical spacing by @var{space}.  The
+default unit is @samp{p}.
+
+If @code{vs} is called without an argument, the vertical spacing is
+reset to the previous value before the last call to @code{vs}.
+
+@vindex .V
+@code{gtroff} creates a warning of type @samp{range} if @var{space} is
+zero or negative; the vertical spacing is then set to the vertical
+resolution (as given in the @code{.V} register).
+
+The read-only number register @code{.v} contains the current vertical
+spacing; it is associated with the current environment
+(@pxref{Environments}).
+@endDefreq
 
 @c XXX example
 
 @ignore
-@example
+@Example
 ... .sz macro example?? ...
-@end example
+@endExample
 @end ignore
 
 @c ---------------------------------------------------------------------
@@ -5785,32 +6602,33 @@ Some devices may only have certain permissible sizes, in which case
 @cindex unit, @code{s}
 @cindex @code{z} unit
 @cindex unit, @code{z}
-@findex ps
-@findex cs
-@findex tkf
-@findex \H
-@findex \s
-A @dfn{scaled point} is equal to 1/@var{sizescale} points, where
-@var{sizescale} is specified in the @file{DESC} file (1@w{ }by default.)
-There is a new scale indicator @samp{z} which has the effect of
-multiplying by @var{sizescale}.  Requests and escape sequences in
-@code{gtroff} interpret arguments that represent a point size as being
-in units of scaled points, but they evaluate each such argument using a
-default scale indicator of @samp{z}.  Arguments treated in this way are
-the argument to the @code{ps} request, the third argument to the
-@code{cs} request, the second and fourth arguments to the @code{tkf}
-request, the argument to the @code{\H} escape sequence, and those
-variants of the @code{\s} escape sequence that take a numeric expression
-as their argument (see below).
+@rqindex ps
+@rqindex cs
+@rqindex tkf
+@esindex \H
+@esindex \s
+A @dfn{scaled point} is equal to @math{1/@var{sizescale}} points,
+where @var{sizescale} is specified in the @file{DESC} file (1@w{ }by
+default).  There is a new scale indicator @samp{z} which has the
+effect of multiplying by @var{sizescale}.  Requests and escape
+sequences in @code{gtroff} interpret arguments that represent a point
+size as being in units of scaled points, but they evaluate each such
+argument using a default scale indicator of @samp{z}.  Arguments
+treated in this way are the argument to the @code{ps} request, the
+third argument to the @code{cs} request, the second and fourth
+arguments to the @code{tkf} request, the argument to the @code{\H}
+escape sequence, and those variants of the @code{\s} escape sequence
+that take a numeric expression as their argument (see below).
 
 For example, suppose @var{sizescale} is@w{ }1000; then a scaled point
-will be equivalent to a millipoint; the request @w{@samp{.ps 10.25}} is
+is equivalent to a millipoint; the request @w{@samp{.ps 10.25}} is
 equivalent to @w{@samp{.ps 10.25z}} and thus sets the point size to
 10250@w{ }scaled points, which is equal to 10.25@w{ }points.
 
-It would make no sense to use the @samp{z} scale indicator in a numeric
+@code{gtroff} disallows the use of the @samp{z} scale indicator in
+instances where it would make no sense, such as a numeric
 expression whose default scale indicator was neither @samp{u} nor
-@samp{z}, and so @code{gtroff} disallows this.  Similarly it would make
+@samp{z}.  Similarly it would make
 no sense to use a scaling indicator other than @samp{z} or @samp{u} in a
 numeric expression whose default scale indicator was @samp{z}, and so
 @code{gtroff} disallows this as well.
@@ -5821,18 +6639,36 @@ equal to @samp{1m}.  Be sure not to confuse the @samp{s} and @samp{z}
 scale indicators.
 
 @vindex .s
-@vindex .ps
-The number register @code{.s} returns the point size in points as decimal
-fraction.  There is also a new number register @code{.ps} that returns
-the point size in scaled points.
+@Defreg {.ps}
+A read-only number register returning the point size in scaled points.
+
+@code{.ps} is associated with the current environment
+(@pxref{Environments}).
+@endDefreg
 
-@vindex .psr
-@vindex .sr
 @cindex last-requested point size register
+@cindex point size, last-requested
+@vindex .ps
+@vindex .s
+@Defreg {.psr}
+@Defregx {.sr}
 The last-requested point size in scaled points is contained in the
-@code{.psr} number register.  The last requested point size in points as
-a decimal fraction can be found in @code{.sr}.  This is a string-valued
-register.
+@code{.psr} read-only number register.  The last requested point size
+in points as a decimal fraction can be found in @code{.sr}.  This is a
+string-valued read-only number register.
+
+Note that the requested point sizes are device-independent, whereas
+the values returned by the @code{.ps} and @code{.s} registers are not.
+For example, if a point size of 11@dmn{pt} is requested for a DVI
+device, 10.95@dmn{pt} are actually used (as specified in the
+@file{DESC} file).
+
+Both registers are associated with the current environment
+(@pxref{Environments}).
+@endDefreg
+
+The @code{\s} escape has the following syntax for working with
+fractional type sizes:
 
 @table @code
 @item \s[@var{n}]
@@ -5848,7 +6684,7 @@ expression with a default scale indicator of @samp{z}.
 @itemx \s'-@var{n}'
 @itemx \s+'@var{n}'
 @itemx \s-'@var{n}'
-Increase or resp.@: decrease the point size by @var{n} scaled points;
+Increase or or decrease the point size by @var{n} scaled points;
 @var{n} is a numeric expression with a default scale indicator of
 @samp{z}.
 @end table
@@ -5858,32 +6694,44 @@ Increase or resp.@: decrease the point size by @var{n} scaled points;
 
 @c =====================================================================
 
-@node Strings, Conditionals and Loops, Sizes, Programming Tutorial
+@node Strings, Conditionals and Loops, Sizes, gtroff Reference
 @section Strings
 @cindex strings
 
-@findex ds
 @code{gtroff} has string variables, which are entirely for user
-convenience (i.e.@: there are no built-in strings).  They are defined
-via the @code{ds} request.
+convenience (i.e.@: there are no built-in strings exept @code{.T}, but
+even this is a read-write string variable).
 
-@example
-.ds UX \s-1UNIX\s0\u\s-3tm\s0\d
-@end example
-
-@findex \*
 @cindex string interpolation
 @cindex string expansion
 @cindex interpolation of strings
 @cindex expansion of strings
-They are interpolated, or expanded in-place, via the @code{\*} escape:
+@Defreq {ds, name [@Var{string}]}
+@Defescx {\\*, , n, }
+@Defescx {\\*, @lparen{}, nm, }
+@Defescx {\\*, @lbrack{}, name, @rbrack{}}
+Define and access a string variable @var{name} (one-character name
+@var{n}, two-character name @var{nm}).  If @var{name} already exists,
+@code{ds} overwrites the previous definition.
 
-@example
+Example:
+
+@Example
+.ds UX \s-1UNIX\s0\u\s-3tm\s0\d
+.
 The \*(UX Operating System
-@end example
+@endExample
+
+The @code{\*} escape @dfn{interpolates} (expands in-place) a
+previously-defined string variable.  To be more precise, the stored
+string is pushed onto the input stack which is then parsed by
+@code{gtroff}.  Similar to number registers, it is possible to nest
+strings, i.e. a string variables can be called within string
+variables.
 
-If the string named by the @code{\*} does not exist, the escape will be
-replaced by nothing.
+If the string named by the @code{\*} does not exist, it is defined as
+empty, and a warning of type @samp{mac} is emitted (see
+@ref{Debugging}, for more details).
 
 @cindex comments, with @code{ds}
 @strong{Caution:} Unlike other requests, the second argument to the
@@ -5891,125 +6739,240 @@ replaced by nothing.
 This means that comments on a line with such a request can introduce
 unwanted space into a string.
 
-@example
+@Example
 .ds UX \s-1UNIX\s0\u\s-3tm\s0\d \" UNIX trademark
-@end example
+@endExample
 
 @noindent
 Instead the comment should be put on another line or have the comment
 escape adjacent with the end of the string.
 
-@example
+@Example
 .ds UX \s-1UNIX\s0\u\s-3tm\s0\d\"  UNIX trademark
-@end example
+@endExample
 
 @cindex trailing quotes
 @cindex quotes, trailing
 @cindex leading spaces with @code{ds}
 @cindex spaces with @code{ds}
-To produce leading space the string can be started with a double quote.
-No trailing quote is needed; in fact, any trailing quote is included in
-your string.
+To produce leading space the string can be started with a double
+quote.  No trailing quote is needed; in fact, any trailing quote is
+included in your string.
 
-@example
+@Example
 .ds sign "           Yours in a white wine sauce,
-@end example
-
-@findex as
-@cindex appending to strings
-@cindex strings, appending
-The @code{as} request will append a string to another string.  It works
-similar to the @code{ds} request except that it appends the second
-argument onto the string named by the first argument.
-
-@example
-.as sign " with shallots, onions and garlic,
-@end example
+@endExample
 
-@findex \@key{RET}
+@esindex \@key{RET}
 @cindex multi-line strings
 @cindex strings, multi-line
 @cindex newline character in strings, escaping
 @cindex escaping newline characters in strings
 Strings are not limited to a single line of text.  A string can span
-several lines by escaping the newlines with a backslash.  The resulting
-string will be stored @emph{without} the newlines.
+several lines by escaping the newlines with a backslash.  The
+resulting string is stored @emph{without} the newlines.
 
-@example
+@Example
 .ds foo lots and lots \
 of text are on these \
 next several lines
-@end example
+@endExample
 
-@findex substring
-@cindex substrings
-Rudimentary string manipulation routines are given with the
-@code{substring} and @code{length} requests.  The former has the
-following syntax:
+It is not possible to have real newlines in a string.
 
-@example
-.substring @var{xx} @var{n1} [@var{n2}]
-@end example
+@cindex name space of macros and strings
+@cindex macros, shared name space with strings
+@cindex strings, shared name space with macros
+Strings, macros, and diversions (and boxes) share the same name space.
+Internally, even the same mechanism is used to store them.  This has
+some interesting consequences.  For example, it is possible to call a
+macro with string syntax and vice versa.
 
-@noindent
-It replaces the string in register@w{ }@var{xx} with the substring
-defined by the indices @var{n1} and@w{ }@var{n2}.  The first character
-in the string has index one.  If @var{n2} is omitted, it is taken to be
-equal to the string's length.  If the index value @var{n1} or @var{n2}
-is negative or zero, it will be counted from the end of the string,
-going backwards: The last character has index@w{ }0, the character
-before the last character has index@w{ }-1, etc.
+@Example
+.de xxx
+a funny test.
+..
+This is \*[xxx]
+    @result{} This is a funny test.
 
-@findex length
-@cindex length of a string
-@cindex string, length of
-Here the syntax of the @code{length} request:
+.ds yyy a funny test
+This is
+.yyy
+    @result{} This is a funny test.
+@endExample
 
-@example
-.length @var{xx} @var{string}
-@end example
+Diversions and boxes can be also called with string syntax.  It is not
+possible to pass arguments to a macro if called with @code{\*}.
 
-@noindent
-It computes the length of @var{string} and returns it in the number
-register@w{ }@var{xx} (which is not necessarily defined before).
+Another consequence is that you can copy one-line diversions or boxes
+to a string.
 
-@ignore
-@findex rn
-@code{rn}
+@Example
+.di xxx
+a \fItest\fR
+.br
+.di
+.ds yyy This is \*[xxx]\c
+\*[yyy].
+    @result{} @r{This is a }@i{test}.
+@endExample
 
-@c XXX
+@noindent
+As the previous example shows, it is possible to store formatted
+output in strings.  The @code{\c} escape prevents the insertion of an
+additional blank line in the output.
 
-@findex rm
-@code{rm}
+Copying diversions longer than a single output line produces
+unexpected results.
 
-@c XXX
+@Example
+.di xxx
+a funny
+.br
+test
+.br
+.di
+.ds yyy This is \*[xxx]\c
+\*[yyy].
+    @result{} test This is a funny.
+@endExample
+
+Usually, it is not predictable whether a diversion contains one or
+more output lines, so this mechanism should be avoided.  With
+@acronym{UNIX} @code{troff}, this was the only solution to strip off a
+final newline from a diversion.  Another disadvantage is that the
+spaces in the copied string are already formatted, making them
+unstretchable.  This can cause ugly results.
+
+@rqindex chop
+@rqindex unformat
+A clean solution to this problem is available in GNU @code{troff},
+using the requests @code{chop} to remove the final newline of a
+diversion, and @code{unformat} to make the horizontal spaces
+stretchable again.
+
+@Example
+.box xxx
+a funny
+.br
+test
+.br
+.box
+.chop xxx
+.unformat xxx
+This is \*[xxx].
+    @result{} This is a funny test.
+@endExample
 
-@findex als
-@code{als}
+@xref{Gtroff Internals}, for more information.
+@endDefreq
 
-@c XXX
+@cindex appending to strings
+@cindex strings, appending
+@Defreq {as, name [@Var{string}]}
+The @code{as} request is similar to @code{ds} but appends @var{string}
+to the string stored as @var{name} instead of redefining it.  If
+@var{name} doesn't exist yet, it is created.
 
-@findex chop
-@code{chop}
+@Example
+.as sign " with shallots, onions and garlic,
+@endExample
+@endDefreq
 
-@c XXX
-@end ignore
+Rudimentary string manipulation routines are given with the next two
+requests.
+
+@cindex substring
+@Defreq {substring, str n1 [@Var{n2}]}
+Replace the string in register@w{ }@var{str} with the substring
+defined by the indices @var{n1} and@w{ }@var{n2}.  The first character
+in the string has index one.  If @var{n2} is omitted, it is taken to
+be equal to the string's length.  If the index value @var{n1} or
+@var{n2} is negative or zero, it is counted from the end of the
+string, going backwards: The last character has index@w{ }0, the
+character before the last character has index@w{ }@minus{}1, etc.
+
+@Example
+.ds xxx abcdefgh
+.substring xxx 2 -3
+\*[xxx]
+    @result{} bcde
+@endExample
+@endDefreq
 
+@cindex length of a string
+@cindex string, length of
+@Defreq {length, reg str}
+Compute the length of @var{str} and returns it in the number
+register@w{ }@var{reg}.  If @var{reg} doesn't exist, it is created.
+
+@Example
+.ds xxx abcdefgh
+.length yyy xxx
+\n[yyy]
+    @result{} 8
+@endExample
+@endDefreq
+
+@cindex rename request
+@cindex rename macro
+@cindex rename string
+@Defreq {rn, xx yy}
+Rename the request, macro, or string @var{xx} to @var{yy}.
+@endDefreq
+
+@cindex remove request
+@cindex remove macro
+@cindex remove string
+@Defreq {rm, xx}
+Remove the request, macro, or string @var{xx}.  @code{gtroff} treats
+subsequent invocations as if the object had never been defined.
+@endDefreq
+
+@cindex alias
+@Defreq {als, new old}
+Create an alias named @var{new} for the request, string, macro, or
+diversion object named @var{old}.  The new name and the old name are
+exactly equivalent (it is similar to a hard rather than a soft
+link). If @var{old} is undefined, @code{gtroff} generates a warning of
+type @samp{mac} and ignores the request.
+@endDefreq
+
+@Defreq {chop, xx}
+Remove (chop) the last character from the macro, string, or diversion
+named @var{xx}. This is useful for removing the newline from the end
+of diversions that are to be interpolated as strings.  This command
+can be used repeatedly; see @ref{Gtroff Internals}, for details on
+nodes inserted by @code{gtroff} automatically.
+@endDefreq
 
 @xref{Identifiers}, and @ref{Comments}.
 
 
 @c =====================================================================
 
-@node Conditionals and Loops, Writing Macros, Strings, Programming Tutorial
+@node Conditionals and Loops, Writing Macros, Strings, gtroff Reference
 @section Conditionals and Loops
 @cindex conditionals and loops
 @cindex loops and conditionals
 
-@findex if@r{, operators to use with it}
-@findex while@r{, operators to use with it}
-In @code{if} and @code{while} requests, there are several more operators
-available:
+@menu
+* Operators in Conditionals::
+* if-else::
+* while::
+@end menu
+
+@c ---------------------------------------------------------------------
+
+@node Operators in Conditionals, if-else, Conditionals and Loops, Conditionals and Loops
+@subsection Operators in Conditionals
+
+@rqindex if
+@rqindex while
+@cindex @code{if}, operators to use with it
+@cindex @code{while}, operators to use with it
+In @code{if} and @code{while} requests, there are several more
+operators available:
 
 @table @code
 @item e
@@ -6017,88 +6980,138 @@ available:
 True if the current page is even or odd numbered (respectively).
 
 @item n
-@findex nroff
-True if the document is being processed in nroff mode.
+@rqindex nroff
+True if the document is being processed in nroff mode (i.e., the
+@code{.nroff} command has been issued).
 
 @item t
-@findex troff
-True if the document is being processed in troff mode.
+@rqindex troff
+True if the document is being processed in troff mode (i.e., the
+@code{.troff} command has been issued).
+
+@item v
+Always false.
 
 @item '@var{xxx}'@var{yyy}'
 True if the string @var{xxx} is equal to the string @var{yyy}.  Other
-characters can be used in place of the single quotes.
-@c XXX (Which?)
-The strings are ``formatted'' before being compared.
-@c XXX (?)
+characters can be used in place of the single quotes; the same set of
+delimiters as for the @code{\D} escape is used (@pxref{Escapes}).
+@code{gtroff} formats the strings before being compared:
+
+@Example
+.ie "|"\fR|\fP" \
+true
+.el \
+false
+    @result{} true
+@endExample
 
-@item r@var{xxx}
+@noindent
+The resulting motions, character sizes, and fonts have to
+match,@footnote{The created output nodes must be identical.
+@xref{Gtroff Internals}.} and not the individual motion, size, and
+font requests.  In the previous example, @samp{|} and @samp{\fR|\fP}
+both result in a roman @samp{|} character with the same point size and
+at the same location on the page, so the strings are equal.  If
+@samp{.ft@w{ }I} had been added before the @samp{.ie}, the result
+would be ``false'' because (the first) @samp{|} produces an italic
+@samp{|} rather than a roman one.
+
+@item r @var{xxx}
 True if there is a number register named @var{xxx}.
 
-@item d@var{xxx}
+@item d @var{xxx}
 True if there is a string, macro, diversion, or request named @var{xxx}.
 
-@item c@var{ch}
-@findex char
+@item c @var{ch}
+@rqindex char
 True if there is a character @var{ch} available; @var{ch} is either an
 @acronym{ASCII} character or a special character (@code{\(@var{ch}} or
-@code{\[@var{ch}]}); the condition will also be true if @var{ch} has
-been defined by the @code{char} request.
+@code{\[@var{ch}]}); the condition is also true if @var{ch} has been
+defined by the @code{char} request.
 @end table
 
-@menu
-* if-else::                     
-* while::                       
-@end menu
+Note that these operators can't be combined with other operators like
+@samp{:} or @samp{&}; only a leading @samp{!} (without whitespace
+between the exclamation mark and the operator) can be used to negate
+the result.
 
-@c ---------------------------------------------------------------------
+@Example
+.nr xxx 1
+.ie !r xxx \
+true
+.el \
+false
+    @result{} false
+@endExample
 
-@node if-else, while, Conditionals and Loops, Conditionals and Loops
-@subsection if-else
-@cindex if-else
+A whitespace after @samp{!} always evaluates to zero (this bizarre
+behaviour is due to compatibility with @acronym{UNIX} @code{troff}).
 
-@code{gtroff} has if-then-else constructs like other languages, although
-the formatting can be painful.
+@Example
+.nr xxx 1
+.ie ! r xxx \
+true
+.el \
+false
+    @result{} r xxx true
+@endExample
 
-@findex if
-The @code{if} request has the following syntax:
+It is possible to omit the whitespace before the argument to the
+@samp{r}, @samp{d}, and @samp{c} operators.
 
-@example
-.if @var{expr} @var{anything}
-@end example
+@xref{Expressions}.
 
-@noindent
-where @var{expr} is the expression to be evaluated; @var{anything} (the
-remainder of the line) will be executed if @var{expr} evaluates to
-non-zero (true).  @var{anything} will be interpreted as though it was on
-a line by itself.  @xref{Expressions}, for more info.
+@c ---------------------------------------------------------------------
 
-Here are some examples:
+@node if-else, while, Operators in Conditionals, Conditionals and Loops
+@subsection if-else
+@cindex if-else
 
-@example
-.if t .ls 2				\" double spacing in troff
-.if 0 .ab how'd this happen?
-@end example
+@code{gtroff} has if-then-else constructs like other languages, although
+the formatting can be painful.
 
-@findex ie
-@findex el
-An if-then-else is written using two requests @code{ie} and @code{el}.
+@Defreq {if, expr anything}
+Evaluate the expression @var{expr}, and executes @var{anything} (the
+remainder of the line) if @var{expr} evaluates to non-zero (true).
+@var{anything} is interpreted as though it was on a line by itself
+(except that leading spaces are swallowed).  @xref{Expressions}, for
+more info.
+
+@Example
+.nr xxx 1
+.nr yyy 2
+.if ((\n[xxx] == 1) & (\n[yyy] == 2)) true
+    @result{} true
+@endExample
+@endDefreq
+
+@c XXX .nop request
+
+@Defreq {ie, expr anything}
+@Defreqx {el, anything}
+Use the @code{ie} and @code{el} requests to write an if-then-else.
 The first request is the `if' part and the latter is the `else' part.
 
-@c XXX example
-
-@example
-.ie
-.el
-@end example
-
-@findex \@{
-@findex \@}
-In many cases more than one request is to be executed as a result of any
-of these requests.  This can be done using the @code{\@{} and @code{\@}}
+@Example
+.ie n .ls 2 \" double spacing in nroff
+.el   .ls 1 \" single spacing in troff
+@endExample
+@endDefreq
+
+@c this is a bug in makeinfo: you can't have `@{' as an argument
+@c to deffn
+
+@esindex \@{
+@esindex \@}
+@c @Defesc {\\@@@{, , , }
+@c @Defescx {\\@@@}, , , }
+In many cases, an if (or if-else) construct needs to execute more than
+one request.  This can be done using the @code{\@{} and @code{\@}}
 escapes.  The following example shows the possible ways to use these
 escapes (note the position of the opening and closing braces).
 
-@example
+@Example
 .ie t \@{\
 .    ds lq ``
 .    ds rq ''
@@ -6107,8 +7120,8 @@ escapes (note the position of the opening and closing braces).
 .\@{\
 .    ds lq "
 .    ds rq "\@}
-.ds qq "
-@end example
+@endExample
+@c @endDefesc
 
 @xref{Expressions}.
 
@@ -6118,94 +7131,179 @@ escapes (note the position of the opening and closing braces).
 @subsection while
 @cindex while
 
-@findex while
 @code{gtroff} provides a looping construct using the @code{while}
 request, which is used much like the @code{if} (and related) requests.
-The first argument is an expression which will be evaluated.  The
-@code{while} request will interpret the remainder of the line until the
-expression evaluates to 0 or false.
 
-@example
+@Defreq {while, expr anything}
+Evaluate the expression @var{expr}, and repeatedly execute
+@var{anything} (the remainder of the line) until @var{expr} evaluates
+to@w{ }0.
+
+@Example
 .nr a 0 1
-.while (\na<9) \&\n+a,
-\&\n+a
-@end example
+.while (\na < 9) \@{\
+\n+a,
+.\@}
+\n+a
+    @result{} 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
+@endExample
 
-@noindent
-The preceding example produces:
+Some remarks.
 
-@example
-1, 2, 3, 4, 5, 6, 7, 8, 9, 10
-@end example
+@rqindex de
+@itemize @bullet
+@item
+The body of a @code{while} request is treated like the body of a
+@code{de} request: @code{gtroff} temporarily stores it in a macro
+which is deleted after the loop has been exited.  It can considerably
+slow down a macro if the body of the @code{while} request (within the
+macro) is large.  Each time the macro is executed, the @code{while}
+body is parsed and stored again as a temporary macro.
+
+@Example
+.de xxx
+.  nr num 10
+.  while (\\n[num] > 0) \@{\
+.    \" many lines of code
+.    nr num -1
+.  \@}
+..
+@endExample
 
-@cindex zero width space character
-@cindex character, zero width space
-@cindex space character, zero width
-@findex \&
+@cindex recursive macros
+@cindex macros, recursive
 @noindent
-Note the usage of the @code{\&} escape to avoid a control character at
-the beginning of a line.
+The traditional and ofter better solution (@acronym{UNIX} @code{troff}
+doesn't have the @code{while} request) is to use a recursive macro
+instead which is parsed only once during its definition.
+
+@Example
+.de yyy
+.  if (\\n[num] > 0) \@{\
+.    \" many lines of code
+.    nr num -1
+.    yyy
+.  \@}
+..
+.
+.de xxx
+.  nr num 10
+.  yyy
+..
+@endExample
+
+@noindent
+Note that the number of available recursion levels is set to@w{ }1000
+(this is a compile-time constant value of @code{gtroff}).
+
+@item
+The closing brace of a @code{while} body must end a line.
+
+@Example
+.if 1 \@{\
+.  nr a 0 1
+.  while (\n[a] < 10) \@{\
+.    nop \n+[a]
+.\@}\@}
+    @result{} unbalanced \@{ \@}
+@endExample
+@end itemize
+@endDefreq
+
+@rqindex while
+@cindex @code{break}, in a @code{while} loop
+@cindex @code{continue}, in a @code{while} loop
+@Defreq {break, }
+Break out of a @code{while} loop.  Be sure not to confuse this with
+the @code{br} request (causing a line break).
+@endDefreq
 
-@findex break@r{, in a @code{while} loop}
-@findex continue@r{, in a @code{while} loop}
-The @code{break} request will @dfn{break} out of a while loop.  Be sure
-not to confuse this with the @code{br} request (causing a line break).
-The @code{continue} request will finish the current iteration of a while
-loop, immediately restarting the next iteration.
+@Defreq {continue, }
+Finishes the current iteration of a @code{while} loop, immediately
+restarting the next iteration.
+@endDefreq
 
 @xref{Expressions}.
 
 
 @c =====================================================================
 
-@node Writing Macros, Page Motions, Conditionals and Loops, Programming Tutorial
+@node Writing Macros, Page Motions, Conditionals and Loops, gtroff Reference
 @section Writing Macros
 @cindex writing macros
 @cindex macros, writing
 
-@findex de
-A @dfn{macro} is a collection of text and embedded commands which can be
-invoked multiple times.  Macros are used for defining common operations.
-Macros are defined using the @code{de} request.  This request takes a
-name for the macro as the first argument.  Subsequent lines are copied
-into an internal buffer until the line @code{..} is encountered.  The
-optional second argument to @code{de} can change this ending token.
+A @dfn{macro} is a collection of text and embedded commands which can
+be invoked multiple times.  Use macros to define common operations.
 
-Here a small example macro called @samp{P} which will cause a break and
-the insertion of some vertical space.  It could be used to separate
-paragraphs.
+@Defreq {de, name [@Var{end}]}
+Define a new macro named @var{name}.  @code{gtroff} copies subsequent
+lines (starting with the next one) into an internal buffer until it
+encounters the line @samp{..} (two dots).  The optional second
+argument to @code{de} changes this to a macro to @samp{.@var{end}}.
 
-@example
+Note that no leading whitespace is allowed in the line containing the
+ending token (either @samp{..} or the macro @samp{.@var{end}}).
+
+Here a small example macro called @samp{P} which causes a break and
+inserts some vertical space.  It could be used to separate paragraphs.
+
+@Example
 .de P
-.br
-.sp .8v
+.  br
+.  sp .8v
 ..
-@end example
+@endExample
+
+@c XXX add info about macro definitions in macros.
+
+@c XXX give example for end macro.
+
+@c XXX add info about indirect macro calls:
+@c
+@c .de xxx
+@c from yyy\c
+@c ..
+@c
+@c test \*[xxx] test
+@c   => test from yyy test
+
+@c XXX info about common identifier pool for strings, macros, and
+@c     diversions.
+@endDefreq
 
-@findex am
 @cindex appending, to a macro
-The @code{am} request works similarly to @code{de} except it appends
-onto the macro named by the first argument.  So, to make the previously
-defined @samp{P} macro actually do indented instead of block paragraphs,
-is is possible to add the necessary code to the existing macro like
-this:
+@Defreq {am, xx}
+Works similarly to @code{de} except it appends onto the macro named
+@var{xx}.  So, to make the previously defined @samp{P} macro actually
+do indented instead of block paragraphs, add the necessary code to the
+existing macro like this:
 
-@example
+@Example
 .am P
 .ti +5n
 ..
-@end example
-
-@findex als
-@cindex aliases, macro
-@cindex macro aliases
-Macros can be aliased with the @code{als} request.
-
-@c XXX example
+@endExample
+@endDefreq
+
+@cindex alias
+@Defreq {als, new old}
+Create an alias named @var{new} for the request, string, macro, or
+diversion object named @var{old}.  The new name and the old name are
+exactly equivalent (it is similar to a hard rather than a soft
+link). If @var{old} is undefined, @code{gtroff} generates a warning of
+type @samp{mac} and ignores the request.
+
+The @code{de}, @code{am}, @code{di}, @code{da}, @code{ds},
+and @code{as} requests only create a new object if the name
+of the macro, diversion or string diversion is currently
+undefined or if it is defined to be a request; normally
+they modify the value of an existing object.
+@endDefreq
 
 @menu
-* Copy-in Mode::                
-* Parameters::                  
+* Copy-in Mode::
+* Parameters::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -6215,14 +7313,19 @@ Macros can be aliased with the @code{als} request.
 @cindex copy-in mode
 @cindex mode, copy-in
 
-@findex \n@r{, when reading test for a macro}
-@findex \$@r{, when reading test for a macro}
-@findex \*@r{, when reading test for a macro}
-@findex \\@r{, when reading test for a macro}
-@findex \@key{RET}@r{, when reading test for a macro}
-When @code{gtroff} reads in the text for a macro or diversion it copies
+@esindex \n
+@esindex \$
+@esindex \*
+@esindex \\
+@esindex \@key{RET}
+@cindex @code{\n}, when reading text for a macro
+@cindex @code{\$}, when reading text for a macro
+@cindex @code{\*}, when reading text for a macro
+@cindex @code{\\}, when reading text for a macro
+@cindex \@key{RET}, when reading text for a macro
+When @code{gtroff} reads in the text for a macro or diversion, it copies
 the text (including request lines, but excluding escapes) into an
-internal buffer.  Escapes will be converted into an internal form,
+internal buffer.  Escapes are converted into an internal form,
 except for @code{\n}, @code{\$}, @code{\*}, @code{\\} and
 @code{\@key{RET}} which are evaluated and inserted into the text where
 the escape was located.  This is known as @dfn{copy-in} mode or
@@ -6233,10 +7336,9 @@ evaluated (either at copy-in time or at the time of use) by insulating
 the escapes with an extra backslash.  Compare this to the @code{\def}
 and @code{\edef} commands in @TeX{}.
 
-For example, the following will result in the numbers 20 and@c{ }10
-being printed:
+The following example prints the numbers 20 and@w{ }10:
 
-@example
+@Example
 .nr x 20
 .de y
 .nr x 10
@@ -6244,7 +7346,7 @@ being printed:
 \&\\nx
 ..
 .y
-@end example
+@endExample
 
 @c ---------------------------------------------------------------------
 
@@ -6252,7 +7354,6 @@ being printed:
 @subsection Parameters
 @cindex parameters
 
-@findex \$
 @vindex .$
 The arguments to a macro can be examined using a variety of escapes.
 The number of arguments is available in the @code{.$} number register.
@@ -6260,95 +7361,107 @@ Any individual argument can be retrieved with one of the following
 escapes:
 
 @cindex copy-in mode, and macro arguments
+@Defesc {\\$, n, , }
+@Defescx {\\$, @lparen{}, nn, }
+@Defescx {\\$, @lbrack{}, nnn, @rbrack{}}
 The escapes @code{\$@var{n}}, @code{\$(@var{nn}} and
-@code{\$[@var{nnn}]} will result in the @var{n}th, @var{nn}th or
-@var{nnn}th argument.  As usual, the first form only accepts a single
-number (larger than zero), the second only a two-digit number (larger or
-equal to@w{ }10), and the third any positive integer value (larger than
-zero).  Macros can have an unlimited number of arguments.  Note that due
-to copy-in mode, two backslashes should be used on these in actual use
-to prevent interpolation until the macro is actually invoked.
-
-@findex shift
-The request @code{shift} will shift the arguments 1@w{ }position, or as
+@code{\$[@var{nnn}]} retrieve the @var{n}@dmn{th}, @var{nn}@dmn{th} or
+@var{nnn}@dmn{th} argument.  As usual, the first form only accepts a
+single number (larger than zero), the second a two-digit number (larger
+or equal to@w{ }10), and the third any positive integer value (larger
+than zero).  Macros can have an unlimited number of arguments.  Note
+that due to copy-in mode, use two backslashes on these in actual use to
+prevent interpolation until the macro is actually invoked.
+@endDefesc
+
+@Defreq {shift, [@Var{n}]}
+Shifts the arguments 1@w{ }position, or as
 many positions as specified by its argument.  After executing this
-request, argument@w{ }@var{i} will become argument @var{i}-@var{n};
-arguments 1 to@w{ }@var{n} will no longer be available.  Shifting by
+request, argument@w{ }@var{i} becomes argument @var{i}-@var{n};
+arguments 1 to@w{ }@var{n} are no longer available.  Shifting by
 negative amounts is currently undefined.
+@endDefreq
 
-@findex \$*
-@findex \$@@
+@Defesc {\\$*, , , }
+@Defescx {\\$@@, , , }
 In some cases it is convenient to use all of the arguments at once (for
 example, to pass the arguments along to another macro).  The @code{\$*}
-escape is the concatenation of all the arguments separated by spaces.  A
-similar escape is @code{\$@@}, which is the concatenation of all the
+escape concatenates all the arguments separated by spaces.  A
+similar escape is @code{\$@@}, which concatenates all the
 arguments with each surrounded by double quotes, and separated by
 spaces.
+@endDefesc
 
-@findex \$0
-@findex als@r{, use with @code{\$0}}
-The @code{\$0} escape is the name by which the current macro was
-invoked.  The @code{als} request can make a macro have more than one
-name.
+@rqindex als
+@cindex @code{als}, use with @code{\$0}
+@Defesc {\\$0, , , }
+The name used to invoke the current macro.
+The @code{als} request can make a macro have more than one name.
 
-@example
+@Example
 .de vl
 .ie \\n(.$=1 .ds Vl Pre-Release Version
 .el          .ds Vl Version \\$3, \\$4.
 ..
-@end example
+@endExample
 
+@noindent
 This would be called as
 
-@example
-.vl $Id: groff.texinfo,v 1.40 2000/06/18 10:13:51 wlemb Exp $
-@end example
+@Example
+.vl $Id: groff.texinfo,v 1.74 2001/04/16 14:47:18 wlemb Exp $
+@endExample
+@endDefesc
 
 @xref{Request Arguments}.
 
 
 @c =====================================================================
 
-@node Page Motions, Drawing Requests, Writing Macros, Programming Tutorial
+@node Page Motions, Drawing Requests, Writing Macros, gtroff Reference
 @section Page Motions
 @cindex page motions
 @cindex motions, page
 
-@findex sp@r{, as vertical page motion}
+@cindex @code{sp}, as vertical page motion
+@Defreq {sp, [@Var{len}]}
 Motions up and down the page can be done with the @code{sp} request.
 However, this causes a break so that the actual effect is to move to the
 left margin and then to the specified location.
+@endDefreq
 
-@findex mk
-@findex rt
+@Defreq {mk, [@Var{reg}]}
+@Defreqx {rt, reg}
 The request @code{mk} can be used to mark a location on a page, for
 movement to later.  This request takes a register name as an argument in
-which to store the current page location.  With no argument it will
-store the location in an internal register.  The results of this can be
+which to store the current page location.  With no argument it
+stores the location in an internal register.  The results of this can be
 used later by the @code{rt} or the @code{sp} request.  The @code{rt}
-request will return @emph{upwards} to the location given in the register
-name given as an argument, with no argument it will return to the
-location marked with the @code{mk} request
+request returns @emph{upwards} to the location given in the register
+name given as an argument; with no argument it returns to the
+location marked with the @code{mk} request.
 
 @c XXX example
 @ignore
-@example
+@Example
 ... dual column example ...
-@end example
+@endExample
 @end ignore
+@endDefreq
 
 The following escapes give fine control of movements about the page.
 
-@findex \v
 @cindex vertical motion
 @cindex motion, vertical
-The @code{\v'@var{e}'} enables arbitrary vertical motion from the
+@Defesc {\\v, ', e, '}
+The @code{\v'@var{e}'} escape enables arbitrary vertical motion from the
 current location on the page.  The argument@w{ }@var{e} specifies the
 distance to move; positive is downwards and negative upwards.  The
-default unit for this escape is vertical spaces, @code{v}'s.  Beware,
-however, that @code{gtroff} will leave text processing to continue
-wherever the motion ends, so to avoid interference with text processing,
-motions should be balanced.
+default unit for this escape @samp{v}.  Beware, however, that
+@code{gtroff} continues text processing at the point where the motion
+ends, so you should always balance motions to avoid interference with
+text processing.
+@endDefesc
 
 There are some special case escapes for vertical motion.
 
@@ -6363,33 +7476,37 @@ move upwards@w{ }.5@dmn{v}.
 move down@w{ }.5@dmn{v}.
 @end ftable
 
-@findex \h
 @cindex inserting horizontal space
 @cindex horizontal space
 @cindex space, horizontal
-Horizontal motions can be done via the @code{\h'@var{e}'} escape.  The
+@Defesc {\\h, ', e, '}
+The @code{\h'@var{e}'} escape provides horizontal motions.  The
 expression@w{ }@var{e} indicates how far to move: positive is rightwards
 and negative leftwards.
+@c XXX Is there a default unit for this?
+@endDefesc
 
 There are a number of special case escapes for horizontal motion:
 
 @ftable @code
 @item \@key{SP}
-an unbreakable and unpaddable (i.e.@: not expanded during filling)
+An unbreakable and unpaddable (i.e.@: not expanded during filling)
 space.  (Note: This is a backslash followed by a space.)
 
 @item \~
-an unbreakable space that stretches like a normal inter-word space when
-a line is adjusted.
+An unbreakable space that stretches like a normal inter-word space
+when a line is adjusted.
 
 @item \|
-a 1/6th em space.
+A 1/6@dmn{th} em space.  Ignored for tty output devices (rounded to
+zero).
 
 @item \^
-a 1/12th em space.
+A 1/12@dmn{th} em space.  Ignored for tty output devices (rounded to
+zero).
 
 @item \0
-a space the size of a digit.
+A space the size of a digit.
 
 @item \&
 @cindex zero width space character
@@ -6403,28 +7520,26 @@ Like @code{\&} except that it behaves like a character declared with the
 sentence recognition.
 @end ftable
 
-@c XXX example
+The following string sets the @TeX{} logo:
 
-@ignore
-@example
-... tex logo example ...
-@end example
-@end ignore
+@Example
+.ds TeX T\h'-.1667m'\v'.224m'E\v'-.224m'\h'-.125m'X
+@endExample
 
-@findex \w
 @cindex width escape
 @cindex escape, width
-A frequent need is to do horizontal movement based on the width of some
-arbitrary text (e.g.@: given as an argument to a macro).  For that,
-there is the escape @code{\w'@var{text}'} which will interpolate to the
-width of the given @var{text} in basic units.
+@Defesc {\\w, ', text, '}
+Used as @code{\w'@var{text}'},
+returns the width of the specified @var{text} in basic units.
+This allows horizontal movement based on the width of some
+arbitrary text (e.g.@: given as an argument to a macro).
 
 @c XXX example
 
 @ignore
-@example
+@Example
 ... strlen example ...
-@end example
+@endExample
 @end ignore
 
 Font changes may occur in @var{text} which don't affect current
@@ -6448,20 +7563,20 @@ heights and depths of characters.
 
 @item ct
 @vindex ct
-is set according to what kinds of characters occur in @var{text}:
+Defines the kinds of characters occurring in @var{text}:
 
 @table @asis
 @item 0
 only short characters, no descenders or tall characters.
 
 @item 1
-descender.
+at least one descender.
 
 @item 2
-tall character.
+at least one tall character.
 
 @item 3
-both a descender and a tall character.
+at least one each of a descender and a tall character.
 @end table
 
 @item ssc
@@ -6472,22 +7587,28 @@ to the last character before a subscript.
 @item skw
 @vindex skw
 How far to right of the center of the last character in the @code{\w}
-argument, the center of an accent from a Roman font should be placed
+argument, the center of an accent from a roman font should be placed
 over that character.
 @end table
+@endDefesc
 
-@findex \k
-@vindex .k
-@code{\k}
+@Defesc {\\k, ', x, '}
+Stores the current horizontal position in register @var{x}.
+Use this, for example, to return to the beginning of a string
+for highlighting or other decoration.
+@endDefesc
 
-@code{.k}
+@Defreg {.k}
+A read-only number register containing the current horizontal output
+position.
+@endDefreg
 
 @c XXX documentation
 
 
 @c =====================================================================
 
-@node Drawing Requests, Traps, Page Motions, Programming Tutorial
+@node Drawing Requests, Traps, Page Motions, gtroff Reference
 @section Drawing Requests
 @cindex drawing requests
 @cindex requests for drawing
@@ -6502,22 +7623,22 @@ information.
 
 All drawing is done via escapes.
 
-@findex \l
 @cindex drawing horizontal lines
 @cindex horizontal line, drawing
 @cindex line, horizontal, drawing
-The @code{\l} escape will draw a line rightwards from the current
-location.  The full syntax for this escape is like this:
+@Defesc {\\l, ', l c, '}
+Draws a line rightwards from the current
+location.  The full syntax for this escape is:
 
-@example
+@Example
 \l'@var{l}@var{c}'
-@end example
+@endExample
 
 @noindent
 where @var{l} is the length of the line to be drawn, starting at the
-current location; positive numbers will draw to the right, and negative
-will draw towards the left.  This can also be specified absolutely
-(i.e.@: with a leading @samp{|}) which will draw back to the beginning
+current location; positive numbers draw to the right, and negative
+numbers draw towards the left.  This can also be specified absolutely
+(i.e.@: with a leading @samp{|}) which draws back to the beginning
 of the line.
 
 @cindex underscore character
@@ -6525,32 +7646,32 @@ of the line.
 @cindex line drawing character
 @cindex character for line drawing
 The optional second parameter @var{c} is a character to draw the line
-with.  If this second argument is not specified, @code{gtroff} will use
+with.  If this second argument is not specified, @code{gtroff} uses
 the underscore character.
 
 @cindex zero width space character
 @cindex character, zero width space
 @cindex space character, zero width
-@findex \&
+@esindex \&
 To separate the two arguments (to prevent @code{gtroff} from
 interpreting a drawing character as a scaling indicator) use @code{\&}.
 
 Here a small useful example:
 
-@example
+@Example
 .de box
 \(br\\$*\(br\l'|0\(rn'\l'|0\(ul'
 ..
-@end example
+@endExample
 
-@noindent
 @opindex |
+@noindent
 Note that this works by outputting a box rule (a vertical line), then
 the text given as an argument and then another box rule.  Then the line
 drawing escapes both draw from the current location to the beginning of
 the @emph{input} line.
+@endDefesc
 
-@findex \L
 @cindex drawing vertical lines
 @cindex vertical line drawing
 @cindex line, vertical, drawing
@@ -6558,25 +7679,28 @@ the @emph{input} line.
 @cindex character for line drawing
 @cindex box rule character
 @cindex character, box rule
-Vertical lines are drawn using the @code{\L} escape.  Its parameters are
-specified similar to the @code{\l} escape.  If the length is positive,
-the movement will be downwards, and upwards for negative values.  The
+@Defesc {\\L, ', l c, '}
+Draws vertical lines.  Its parameters are
+similar to the @code{\l} escape.  The
+movement is downwards for positive values,
+and upwards for negative values.  The
 default character is the box rule character.  As with the vertical
-motion escapes, text processing will blindly continue where the line
+motion escapes, text processing blindly continues where the line
 ends.
 
 @c XXX example
 
 @ignore
-@example
+@Example
 ...box macro...
-@end example
+@endExample
 @end ignore
+@endDefesc
 
-@findex \D
-More flexible drawing functions are available via the @code{\D} escape.
-While the previous escapes will work on a character device, these
-escapes will not.
+@Defesc {\\D, ', command arg @dots{}, '}
+The @code{\D} escape provides a variety of drawing functions.
+While the previous escapes work on a character device, these
+escapes do not.
 
 @table @code
 @item \D'l @var{dx} @var{dy}'
@@ -6586,9 +7710,9 @@ Draw a line from the current location to the relative point specified by
 @c XXX example
 
 @ignore
-@example
+@Example
 ...revised box macro...
-@end example
+@endExample
 @end ignore
 
 @item \D'c @var{d}'
@@ -6630,7 +7754,7 @@ Set the shade of gray to be used for filling solid objects to@w{
 corresponds solid white and 1000 to solid black, and values in between
 correspond to intermediate shades of gray.  This applies only to solid
 circles, solid ellipses and solid polygons.  By default, a level of@w{
-}1000 will be used.
+}1000 is used.
 
 @item \D'p @var{dx1} @var{dy1} @var{dx2} @var{dy2} ...'
 @cindex drawing a polygon
@@ -6642,9 +7766,9 @@ are exhausted, a line is drawn back to the starting point.
 @c XXX example
 
 @ignore
-@example
+@Example
 ... box example (yes, again)...
-@end example
+@endExample
 @end ignore
 
 @item \D'P @var{dx1} @var{dy1} @var{dx2} @var{dy2} ...'
@@ -6653,9 +7777,9 @@ Draw a solid polygon with the same parameters as an outlined polygon.
 @c XXX example
 
 @ignore
-@example
+@Example
 ... shaded box example ...
-@end example
+@endExample
 @end ignore
 
 @item \D't @var{n}'
@@ -6666,37 +7790,39 @@ zero selects the smallest available line thickness.  A negative value
 makes the line thickness proportional to the current point size (this is
 the default behaviour of @code{ditroff}).
 @end table
+@endDefesc
 
-@findex \b
 @cindex pile, character
 @cindex character pile
-The @code{\b} escape will @dfn{pile} a sequence of characters
-vertically, and center it vertically on the current line.  This can be
-used to build large brackets and braces.
+@Defesc {\\b, ', string, '}
+@dfn{Piles} a sequence of characters
+vertically, and centers it vertically on the current line.  Use it
+to build large brackets and braces.
 
-@example
+@Example
 \b'\(lt\(bv\(lk\(bv\(lb'
-@end example
+@endExample
+@endDefesc
 
 @xref{Drawing Functions}.
 
 
 @c =====================================================================
 
-@node Traps, Diversions, Drawing Requests, Programming Tutorial
+@node Traps, Diversions, Drawing Requests, gtroff Reference
 @section Traps
 @cindex traps
 
-@dfn{Traps} are locations, which, when reached, will call a specified
+@dfn{Traps} are locations, which, when reached, call a specified
 macro.  These traps can occur at a given location on the page, at a
 given location in the current diversion, after a certain number of input
 lines or at the end of input.
 
 @menu
-* Page Location Traps::         
-* Diversion Traps::             
-* Input Line Traps::            
-* End-of-input Traps::          
+* Page Location Traps::
+* Diversion Traps::
+* Input Line Traps::
+* End-of-input Traps::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -6706,16 +7832,49 @@ lines or at the end of input.
 @cindex page location traps
 @cindex traps, page location
 
-@c XXX definition of wh request
+@dfn{Page location traps} perform an action when @code{gtroff}
+reaches a certain vertical location on the page.  Page location
+traps have a variety of purposes, including:
+
+@itemize
+@item
+setting headers and footers
+
+@item
+setting body text in multiple columns
+
+@item
+setting footnotes
+@end itemize
+
+@cindex vertical position trap enable register
+@Defreq {vpt, flag}
+@Defregx {.vpt}
+Enables vertical position traps if @var{flag} is non-zero, or disables
+them otherwise.  Vertical position traps are traps set by the @code{wh}
+or @code{dt} requests.  Traps set by the @code{it} request are not
+vertical position traps.  The parameter that controls whether vertical
+position traps are enabled is global.  Initially vertical position traps
+are enabled.  The current setting of this is available in the
+@code{.vpt} read-only number register.
+@endDefreq
+
+@Defreq {wh, dist macro}
+Sets a page location trap.  Positive values for @var{dist} set
+the trap relative to the top of the page; negative values set
+the trap relative to the bottom of the page.
+
+@var{macro} is the name of the macro to execute when the
+trap is sprung.
 
 @cindex page headers
 @cindex page footers
 @cindex headers
 @cindex footers
-Page location traps are frequently used for page headers and footers.
-The following is a simple example of this.
+The following is a simple example of how many macro packages
+set headers and footers.
 
-@example
+@Example
 .de hd                \" Page header
 'sp .5i
 .tl 'Title''date'
@@ -6728,57 +7887,52 @@ The following is a simple example of this.
 ..
 .wh 0   hd            \" trap at top of the page
 .wh -1i fo            \" trap one inch from bottom
-@end example
+@endExample
+@endDefreq
 
-@vindex .t
 @cindex distance to next trap
 @cindex trap, distance
-The number register @code{.t} is the distance to the next trap.
+@Defreg {.t}
+A read-only number register holding the distance to the next trap.
+@endDefreg
 
-@findex ch
 @cindex changing trap location
 @cindex trap, changing location
-The location of a trap can be changed later on with the @code{ch}
-request.  The first argument is the name of the macro to be invoked at
-the trap, and the second argument is the new location for the trap.
+@Defreq {ch, dist macro}
+Changes the location of a trap.
+The first argument is the name of the macro to be invoked at
+the trap, and the second argument is the new location for the trap
+(note that the parameters are specified the opposite of the @code{.wh} request).
 This is useful for building up footnotes in a diversion to allow more
 space at the bottom of the page for them.
 
 @c XXX
 
 @ignore
-@example
+@Example
 ... (simplified) footnote example ...
-@end example
+@endExample
 @end ignore
-
-@findex vpt
-@findex wh
-@vindex .vpt
-@cindex vertical position trap enable register
-The @code{vpt} request will enable vertical position traps if the
-argument is non-zero, disable them otherwise.  Vertical position traps
-are traps set by the @code{wh} or @code{dt} requests.  Traps set by the
-@code{it} request are not vertical position traps.  The parameter that
-controls whether vertical position traps are enabled is global.
-Initially vertical position traps are enabled.  The current setting of
-this is available in the number register @code{.vpt}.
-
-@vindex .trunc
-@findex ne@r{, and the @code{.trunc} register}
-The number register @code{.trunc} contains the amount of vertical space
-truncated by the most recently sprung vertical position trap, or, if the
-trap was sprung by a @code{ne} request, minus the amount of vertical
-motion produced by the @code{ne} request.  In other words, at the point
-a trap is sprung, it represents the difference of what the vertical
-position would have been but for the trap, and what the vertical
-position actually is.
-
-@vindex .ne
-The number register @code{.ne} contains the amount of space that was
-needed in the last @code{ne} request that caused a trap to be sprung.
-Useful in conjunction with the @code{.trunc} register.  @xref{Page
-Control}, for more information.
+@endDefreq
+
+@Defreg {.ne}
+The read-only number register @code{.ne} contains the amount of space
+that was needed in the last @code{ne} request that caused a trap to be
+sprung.  Useful in conjunction with the @code{.trunc} register.
+@xref{Page Control}, for more information.
+@endDefreg
+
+@rqindex ne
+@cindex @code{ne}, and the @code{.trunc} register
+@Defreg {.trunc}
+A read-only register containing the amount of vertical space truncated
+by the most recently sprung vertical position trap, or, if the trap was
+sprung by an @code{ne} request, minus the amount of vertical motion
+produced by the @code{ne} request.  In other words, at the point a trap
+is sprung, it represents the difference of what the vertical position
+would have been but for the trap, and what the vertical position
+actually is.
+@endDefreg
 
 @c ---------------------------------------------------------------------
 
@@ -6787,13 +7941,16 @@ Control}, for more information.
 @cindex diversion traps
 @cindex traps, diversion
 
-@findex dt
-@vindex .t@r{, and diversions}
-Traps can also be set @emph{within} a diversion using the @code{dt}
-request.  Like @code{wh} the first argument is the location of the trap
-and the second argument is the name of the macro to be invoked.  The
-number register @code{.t} will still work within diversions.
+@vindex .t
+@cindex @code{.t}, and diversions
+@Defreq {dt, dist macro}
+Sets a trap @emph{within} a diversion.
+@var{dist} is the first argument is the location of the trap
+(identical to the @code{.wh} request)
+and @var{macro} is the name of the macro to be invoked.  The
+number register @code{.t} still works within diversions.
 @xref{Diversions}, for more information.
+@endDefreq
 
 @c ---------------------------------------------------------------------
 
@@ -6802,31 +7959,25 @@ number register @code{.t} will still work within diversions.
 @cindex input line traps
 @cindex traps, input line
 
-@findex it
-The @code{it} request will set an input line trap.  The format for
-calling this is
-
-@example
-.it @var{n} @var{name}
-@end example
-
-@noindent
-where @var{n} is the number of lines of input which may be read before
-@dfn{springing} the trap, @var{name} is the macro to be invoked.
+@Defreq {it, n macro}
+Sets an input line trap.
+@var{n} is the number of lines of input which may be read before
+@dfn{springing} the trap, @var{macro} is the macro to be invoked.
 Request lines are not counted as input lines.
 
-For example, one possible use is to have a macro which will print the
+For example, one possible use is to have a macro which prints the
 next @var{n}@w{ }lines in a bold font.
 
-@example
+@Example
 .de B
-.it B-end \\$1
+.it \\$1 B-end
 .ft B
 ..
 .de B-end
 .ft R
 ..
-@end example
+@endExample
+@endDefreq
 
 @c ---------------------------------------------------------------------
 
@@ -6835,16 +7986,16 @@ next @var{n}@w{ }lines in a bold font.
 @cindex end-of-input traps
 @cindex traps, end-of-input
 
-@findex em
-The @code{em} request will set a trap at the end of input.  The macro
-specified as an argument will be executed after the last line of the
+@Defreq {em, macro}
+Sets a trap at the end of input.  The @var{macro}
+specified is executed after the last line of the
 input file has been processed.
 
 For example, if the document had to have a section at the bottom of the
 last page for someone to approve it, the @code{em} request could be
 used.
 
-@example
+@Example
 .de approval
 .ne 5v
 .sp |(\\n(.t-6v)
@@ -6856,12 +8007,13 @@ Approved:\t\a
 Date:\t\t\a
 ..
 .em approval
-@end example
+@endExample
+@endDefreq
 
 
 @c =====================================================================
 
-@node Diversions, Environments, Traps, Programming Tutorial
+@node Diversions, Environments, Traps, gtroff Reference
 @section Diversions
 @cindex diversions
 
@@ -6871,49 +8023,62 @@ said to be stored in a macro.  This is used for saving text for output
 at a later time, which is useful for keeping blocks of text on the same
 page, footnotes, tables of contents and indices.
 
-@findex di
-@findex da
-A diversion is initiated by the @code{di} request.  Like the @code{de}
+@c XXX describe top-level diversion
+@c XXX index entry for top-level diversion
+
+@Defreq {di, macro}
+@Defreqx {da, macro}
+Begins a diversion.  Like the @code{de}
 request, it takes an argument of a macro name to divert subsequent text
-into.  The @code{da} macro will append to an existing diversion.
+into.  The @code{da} macro appends to an existing diversion.
 
-@code{di} (resp.@: @code{da}) without an argument ends the diversion.
+@code{di} or @code{da} without an argument ends the diversion.
 
 @c XXX example
 
 @ignore
-@example
+@Example
 ... end-note example ...
-@end example
+@endExample
 @end ignore
+@endDefreq
 
-@vindex .z
-@vindex .d
 @vindex nl
 @vindex .h
 @cindex nested diversions
 @cindex diversion, nested
-Diversions may be nested.  The number register @code{.z} contains the
-name of the current diversion.  The number register @code{.d} contains
-the current vertical place in the diversion.  If not in a diversion it
-is the same as the register @code{nl}.
+@Defreg {.z}
+@Defregx {.d}
+Diversions may be nested.  The read-only number register @code{.z}
+contains the name of the current diversion (this is a string-valued
+register).  The read-only number register @code{.d} contains the current
+vertical place in the diversion.  If not in a diversion it is the same
+as the register @code{nl}.
+@endDefreg
 
 @c XXX more info
 
-@code{.h}
+@Defreg {.h}
+The @dfn{high-water mark} on the current page.  It corresponds to the
+text baseline of the lowest line on the page.  This is a read-only
+register.
+@endDefreg
 
-@vindex dn
-@vindex dl
-After completing a diversion, the built-in number registers @code{dn}
+@Defreg {dn}
+@Defregx {dl}
+After completing a diversion, the read-write number registers @code{dn}
 and @code{dl} contain the vertical and horizontal size of the diversion.
 
 @example
+@group
 .\" Center text both horizontally & vertically
 .de (c
 .br
 .nf
 .di @@c
 ..
+@end group
+@group
 .de )c
 .br
 .di
@@ -6929,36 +8094,39 @@ and @code{dl} contain the vertical and horizontal size of the diversion.
 .fi
 .rr @@s
 ..
+@end group
 @end example
+@endDefreg
 
-@findex \!
 @cindex transparent output
 @cindex output, transparent
-Requests, macros and escapes are interpreted when read into a diversion.
-There are two ways to prevent this; either way will take the given text
-and @dfn{transparently} embed it into the diversion.  The first method
-is to prefix the line with @code{\!}.  This will cause the entire line
-to be transparently inserted into the diversion.  This is useful for
+@Defesc {\\!, , , }
+@Defescx {\\?, , @Var{anything}, \\?}
+Prevents requests, macros and escapes from being
+interpreted when read into a diversion.  This takes the given text
+and @dfn{transparently} embeds it into the diversion.  This is useful for
 macros which shouldn't be invoked until the diverted text is actually
 output.
 
 @c XXX anything is read in copy mode. (what about \! ??)
 
-@findex \?
-The other way is to surround the text by the @code{\?} escape, i.e.
+The @code{\!} escape transparently embeds text up to
+and including the end of the line.
+The @code{\?} escape transparently embeds text until the next
+occurrence of the @code{\?} escape.  For example:
 
-@example
+@Example
 \?@var{anything}\?
-@end example
+@endExample
 
 @noindent
 @var{anything} may not contain newlines; use @code{\!}  to embed
 newlines in a diversion.  The escape sequence @code{\?} is also
 recognized in copy mode and turned into a single internal code; it is
-this code that terminates anything.  Thus the following example will
-print@w{ }4.
+this code that terminates anything.  Thus the following example
+prints@w{ }4.
 
-@example
+@Example
 .nr x 1
 .nf
 .di d
@@ -6974,42 +8142,43 @@ print@w{ }4.
 .di
 .nr x 4
 .f
-@end example
+@endExample
+@endDefesc
 
-@findex asciify
 @cindex unformatting diversions
 @cindex diversion, unformatting
-The @code{asciify} request only exists in order to make certain gross
-hacks work with GNU @code{troff}.  It @dfn{unformats} the diversion
-specified as an argument in such a way that @acronym{ASCII} characters
-that were formatted and diverted will be treated like ordinary input
-characters when the diversion is reread.  For example, the following
-will set register @code{n} to@w{ }1.
-
-@example
+@Defreq {asciify, div}
+@dfn{Unformats} the diversion specified by @var{div}
+in such a way that @acronym{ASCII} and space characters that
+were formatted and diverted are treated like ordinary input
+characters when the diversion is reread.  It can be also used for gross
+hacks; for example, the following sets register @code{n} to@w{ }1.
+
+@Example
 .tr @@.
 .di x
-@@nr\ n\ 1
+@@nr n 1
 .br
 .di
 .tr @@@@
 .asciify x
 .x
-@end example
+@endExample
 
 @xref{Copy-in Mode}.
+@endDefreq
 
 
 @c =====================================================================
 
-@node Environments, I/O, Diversions, Programming Tutorial
+@node Environments, Suppressing output, Diversions, gtroff Reference
 @section Environments
 @cindex environments
 
 It happens frequently that some text should be printed in a certain
 format regardless of what may be in effect at the time, for example, in
 a trap invoked macro to print headers and footers.  To solve this
-@code{gtroff} has @dfn{environments} in which text is processed.  An
+@code{gtroff} processes text in @dfn{environments}.  An
 environment contains most of the parameters that control text
 processing.  It is possible to switch amongst these environments; by
 default @code{gtroff} processes text in environment@w{ }0.  The
@@ -7039,121 +8208,177 @@ These environments may be given arbitrary names (see @ref{Identifiers},
 for more info).  Old versions of @code{troff} only had environments
 named @samp{0}, @samp{1} and@w{ }@samp{2}.
 
-@findex ev
-@vindex .ev
 @cindex switch environments
 @cindex current environment number/name register
-The @code{ev} request will switch to another environment.  The single
-argument is the name of the environment to switch to.  With no argument
-@code{gtroff} will switch back to the previous environment.  There is no
-limit on the number of named environments; they will be created the
-first time that they are referenced.  The @code{.ev} register contains
-the name or number of the current environment.  This is a string-valued
-register.
-
-Note that a call to @code{ev} (with argument) will push the previously
+@Defreq {ev, env}
+@Defregx {.ev}
+Switches to another environment.  The argument @var{env} is the name of
+the environment to switch to.  With no argument, @code{gtroff} switches
+back to the previous environment.  There is no limit on the number of
+named environments; they are created the first time that they are
+referenced.  The @code{.ev} read-only register contains the name or
+number of the current environment.  This is a string-valued register.
+
+Note that a call to @code{ev} (with argument) pushes the previously
 active environment onto a stack.  If, say, environments @samp{foo},
 @samp{bar}, and @samp{zap} are called (in that order), the first
-@code{ev} request without parameter will switch back to environment
-@samp{bar} (which will be popped off the stack), and a second call will
-switch back to environment @samp{foo}.
+@code{ev} request without parameter switches back to environment
+@samp{bar} (which is popped off the stack), and a second call
+switches back to environment @samp{foo}.
 
 @c XXX example
 
 @ignore
-@example
+@Example
 ... page break macro, revised ...
-@end example
+@endExample
 @end ignore
 
-Here is another example:
+Here is an example:
 
-@example
+@Example
 .ev footnote-env
 .fam N
 .ps 6
 .vs 8
 .ll -.5i
 .ev
+
 ...
+
 .ev footnote-env
 \(dg Note the large, friendly letters.
 .ev
-@end example
+@endExample
+@endDefreq
 
-@findex evc
 @cindex copy environment
-To copy an environment into the current one, use the @code{evc} request,
-which takes the name of the environment to copy from as an argument.
+@Defreq {evc, env}
+Copies the environment @var{env} into the current environment.
+@endDefreq
+
+
+@c =====================================================================
+
+@node Suppressing output, I/O, Environments, gtroff Reference
+@section Suppressing output
+@cindex suppressing output
+
+@Defesc {\\O, , num, }
+Disables or enables output depending on the value of @var{num}:
+
+@table @samp
+@item \O0
+Disable any ditroff glyphs from being emitted to the device driver.
+
+@item \O1
+Enable output of glyphs.
+@end table
+
+@vindex opminx
+@vindex opminy
+@vindex opmaxx
+@vindex opmaxy
+@code{\O0} and @code{\O1} also reset the four registers @samp{opminx},
+@samp{opminy}, @samp{opmaxx}, and @samp{opmaxy} to @minus{}1.
+@xref{Register Index}.  These four registers mark the top left and
+bottom right hand corners of a box which encompasses all written glyphs.
+
+The following two forms of @code{\O} are specific to @code{grohtml}.
+
+@table @samp
+@item \O2
+Disable any ditroff glyphs from being emitted to the device driver.  Also
+write out to @code{stderr} the page number and four registers encompassing
+the glyphs previously written since the last call to @code{\O}.
+
+@item \O3
+Enable output of glyphs (the default).  Also write out to @code{stderr}
+the page number and four registers encompassing the glyphs previously
+written since the last call to @code{\O}.
+@end table
+@endDefesc
 
 
 @c =====================================================================
 
-@node I/O, Postprocessor Access, Environments, Programming Tutorial
+@node I/O, Postprocessor Access, Suppressing output, gtroff Reference
 @section I/O
 @cindex i/o
 @cindex input and output requests
 @cindex requests for input and output
 @cindex output and input requests
 
-@findex so
+@code{gtroff} has several requests for including files:
+
 @cindex including a file
 @cindex file inclusion
-The @code{so} request will read in the file given as an argument and
-include it in place of the @code{so} request.  This is quite useful for
-large documents, i.e.@: keeping each chapter in a separate file.
+@Defreq {so, file}
+Reads in the specified @var{file} and
+includes it in place of the @code{so} request.  This is quite useful for
+large documents, e.g.@: keeping each chapter in a separate file.
 @xref{gsoelim}, for more information.
+@endDefreq
 
-@findex mso
-The @code{mso} request is the same as the @code{so} request except that
-the file is searched for in the same directories as
-@file{tmac.@var{name}} is searched for when the @option{-m@var{name}}
-option is specified.
+@Defreq {mso, file}
+Identical to the @code{so} request except that @code{gtroff}
+searches for the specified
+@var{file} in the same directories as macro files for the
+the @option{-m} command line option.  If the file name to be included
+has the form @file{@var{name}.tmac} and it isn't found, @code{mso} tries
+to include @file{tmac.@var{name}} and vice versa.
+@endDefreq
 
-@findex cf
 @cindex transparent output
 @cindex output, transparent
-The @code{cf} and @code{trf} requests are to include a file.  It will
-transparently output the contents of file filename.  Each line is output
+@Defreq {cf, file}
+@Defreqx {trf, file}
+Transparently outputs the contents of @var{file}.  Each line is output
 as it were preceded by @code{\!}; however, the lines are not subject to
 copy mode interpretation.  If the file does not end with a newline, then
-a newline will be added.  For example, to define a macro@w{ }@code{x}
+a newline is added.  For example, to define a macro@w{ }@code{x}
 containing the contents of file@w{ }@file{f}, use
 
-@example
+@Example
 .di x
 .trf f
 .di
-@end example
+@endExample
 
 The request @w{@code{.cf @var{filename}}}, when used in a diversion,
-will embed in the diversion an object which, when reread, will cause the
+embeds an object in the diversion which, when reread, causes the
 contents of @var{filename} to be transparently copied through to the
-output.  In @acronym{UNIX} @code{troff}, the contents of @var{filename}
+output.
+
+In @acronym{UNIX} @code{troff}, the contents of @var{filename}
 is immediately copied through to the output regardless of whether there
 is a current diversion; this behaviour is so anomalous that it must be
 considered a bug.  This request causes a line break.
 
-@findex trf
+@rqindex trf
 With @code{trf}, unlike @code{cf}, the file cannot contain characters
 such as NUL that are not valid @code{gtroff} input characters
 (@pxref{Identifiers}).  This request causes a line break.
+@endDefreq
 
-@findex nx
-The @code{nx} request will force @code{gtroff} to continue processing of
+@Defreq {nx, }
+Forces @code{gtroff} to continue processing of
 the file specified as an argument.
+@endDefreq
 
-@findex rd
-The @code{rd} request will read from standard input, and include what is
+@Defreq {rd, }
+The @code{rd} request reads from standard input, and includes what is
 read as though it were part of the input file.  Text is read until a
 blank line is encountered.
+@endDefreq
 
 @cindex form letters
 @cindex letters, form
-Using these two requests it is easy to set up form letters.  The form
+Using the @code{nx} and @code{rd} requests,
+it is easy to set up form letters.  The form
 letter template is constructed like this:
 
-@example
+@Example
 .ce
 \*(td
 .sp 2
@@ -7165,9 +8390,9 @@ letter template is constructed like this:
 Body of letter.
 .bp
 .nx repeat.let
-@end example
+@endExample
 
-@findex ex
+@rqindex ex
 @noindent
 When this is run, the following file should be redirected in.  Note that
 requests included in this file are executed as though they were part of
@@ -7175,7 +8400,7 @@ the form letter.  The last block of input is the @code{ex} requests
 which tells groff to stop processing.  If this was not there, groff
 would not know when to stop.
 
-@example
+@Example
 Trent A. Fisher
 708 NW 19th Av., #202
 Portland, OR  97209
@@ -7189,100 +8414,106 @@ San Diego, CA  92103
 Dear Mr. Adollar,
 
 .ex
-@end example
+@endExample
 
-@findex pi
-@code{pi}
+@Defreq {pi, pipe}
+Pipes the output of @code{gtroff} to the shell command(s)
+specified by @var{pipe}.  This request must occur before
+@code{gtroff} has a chance to print anything.
+@endDefreq
 
-@c XXX documentation
-
-@findex sy
-The @code{sy} request will allow arbitrary system commands to be
-executed from within a @code{gtroff} document.  The output is not saved
-anyplace, so it is up to the user to do so.
+@Defreq {sy, cmds}
+@Defregx {systat}
+In @dfn{unsafe} mode, executes the shell command(s) specified by
+@var{cmds}.  The output is not saved anyplace, so it is up to the user
+to do so.
 
 @c XXX add info about safer and unsafe mode
 
-For example, the following example will introduce the current time
+For example, the following example introduces the current time
 into a document:
 
 @cindex time, current
 @cindex current time
 @pindex perl
-@example
+@Example
 .sy perl -e 'printf ".nr H %d\\n.nr M %d\\n.nr S %d\\n",\
 	     (localtime(time))[2,1,0]' > /tmp/x\n[$$]
 .so /tmp/x\n[$$]
 .sy rm /tmp/x\n[$$]
 \nH:\nM:\nS
-@end example
+@endExample
 
 @noindent
 Note that this works by having the @code{perl} script (run by @code{sy})
-print out the @code{nr} requests which will set the number registers
+print out the @code{nr} requests which set the number registers
 @samp{H}, @samp{M} and @samp{S}, and then reads those commands in with
 the @code{so} request.
 
-@vindex systat
 @cindex @code{system()} return value register
-The @code{systat} number register contains the return value of the
-@code{system()} function executed by the last @code{sy} request.
+The @code{systat} read-write number register contains the return value
+of the @code{system()} function executed by the last @code{sy} request.
+@endDefreq
 
-@findex open
-The @code{open} request will open a file (specified as the second
-argument) for writing and associate the stream (specified as the first
-argument) with it.
+@Defreq {open, stream file}
+@Defreqx {opena, stream file}
+Opens the specified @var{file} for writing and
+associates the specified @var{stream} with it.
 
-@findex opena
 The @code{opena} is like @code{open}, but if the file exists, append to
 it instead of truncating it.
+@endDefreq
 
-@findex write
 @cindex copy-in mode, and @code{write} requests
 @cindex mode, copy-in, and @code{write} requests
-The @code{write} request will write to the file associated with the
-stream specified by the first argument.  The stream must previously have
+@Defreq {write, stream data}
+Writes to the file associated with the specified @var{stream}.
+The stream must previously have
 been the subject of an open request.  The remainder of the line is
 interpreted as the @code{ds} request reads its second argument: A
-leading @samp{"} will be stripped, and it will be read in copy-in mode.
+leading @samp{"} is stripped, and it is read in copy-in mode.
+@endDefreq
 
-@findex close
-The @code{close} request will close the stream specified by the first
-argument; stream will no longer be an acceptable argument to the
+@Defreq {close, stream}
+Closes the specified @var{stream};
+the stream is no longer an acceptable argument to the
 @code{write} request.
 
 @c XXX example
 
 @ignore
-@example
+@Example
 ... example of open write &c...
-@end example
+@endExample
 @end ignore
+@endDefreq
 
-@findex \V
-The @code{\V} escape will interpolate the contents of the specified
-environment variable, as returned by the function @code{getenv}.  The
-argument to @code{\V} is specified as an identifier, i.e.@:
+@Defesc {\\V, ', xxx, '}
+Interpolates the contents of the specified
+environment variable, as returned by the function @code{getenv}.
+Specify the argument to @code{\V} as an identifier, i.e.@:
 @samp{\V@var{x}}, @samp{\V(@var{xx}} or @samp{\V[@var{xxx}]}.  @code{\V}
 is interpreted in copy-in mode.
+@endDefesc
 
 
 @c =====================================================================
 
-@node Postprocessor Access, Miscellaneous, I/O, Programming Tutorial
+@node Postprocessor Access, Miscellaneous, I/O, gtroff Reference
 @section Postprocessor Access
 @cindex postprocessor access
 @cindex access of postprocessor
 
-There are two escapes which will allow information to be directly given
-to the postprocessor.  This is particularly useful for embedding
+There are two escapes which give information directly to the
+postprocessor.  This is particularly useful for embedding
 @sc{PostScript} into the final document.
 
-@findex \X
-The @code{\X} escape will embed its argument into the @code{gtroff}
+@Defesc {\\X, ', xxx, '}
+Embeds its argument into the @code{gtroff}
 output preceded with @w{@samp{x X}}.
+@endDefesc
 
-@findex \Y
+@Defesc {\\Y, ', xxx, '}
 The @code{\Y} escape is called with an identifier (i.e.@:
 @code{\Y@var{x}}, @code{\Y(@var{xx}} or @code{\Y[@var{xxx}]}).  This is
 approximately equivalent to @samp{\X'\*[@var{xxx}]'}.  However, the
@@ -7290,38 +8521,40 @@ contents of the string or macro @var{xxx} are not interpreted; also it
 is permitted for @var{xxx} to have been defined as a macro and thus
 contain newlines (it is not permitted for the argument to @code{\X} to
 contain newlines).  The inclusion of newlines requires an extension to
-the @acronym{UNIX} @code{troff} output format, and will confuse drivers
+the @acronym{UNIX} @code{troff} output format, and confuses drivers
 that do not know about this extension.
+@endDefesc
 
 @xref{Output Devices}.
 
 
 @c =====================================================================
 
-@node Miscellaneous, Debugging, Postprocessor Access, Programming Tutorial
+@node Miscellaneous, Gtroff Internals, Postprocessor Access, gtroff Reference
 @section Miscellaneous
 @cindex miscellaneous
 
 This section documents parts of @code{gtroff} which cannot (yet) be
 categorized elsewhere in this manual.
 
-@findex nm
 @cindex line numbers
 @cindex numbers, line
-Line numbers can be printed in the left margin using the @code{nm}
-request.  The first argument is the line number of the @emph{next}
-output line; this defaults to@w{ }1.  The second argument indicates on
-which lines numbers will be printed, i.e.@: 5 means put line numbers on
-every 5@w{ }lines; this defaults to@w{ }1.  The third argument is the
+@Defreq {nm, start inc space indent}
+Prints line numbers in the left margin.
+@var{start} is the line number of the @emph{next}
+output line; this defaults to@w{ }1.  @var{inc} indicates on
+which lines numbers are printed, i.e.@: 5 means put line numbers on
+every 5@w{ }lines; this defaults to@w{ }1.  @var{space} is the
 space to be left between the number and the text; this defaults to@w{
 }1.  The fourth argument is the indentation of the line numbers.
 Without arguments, line numbers are turned off.
+@endDefreq
 
 @c XXX xref ln register
 
-@findex nn
-The @code{nn} request will temporarily turn off line numbering.  The
-first argument is the number of lines not to be numbered; this defaults
+@Defreq {nn, [@Var{skip}]}
+Temporarily turns off line numbering.  The
+argument is the number of lines not to be numbered; this defaults
 to@w{ }1.
 
 @c XXX (does this disable incrementing or display?)
@@ -7329,19 +8562,20 @@ to@w{ }1.
 @c XXX example
 
 @ignore
-@example
+@Example
 ... line numbering example ...
-@end example
+@endExample
 @end ignore
+@endDefreq
 
-@findex mc
 @cindex margin characters
 @cindex characters for margins
-Margin characters can be automatically printed to the right of the text
-with the @code{mc} request.  The first argument is the character to be
+@Defreq {mc, char dist}
+Prints margin characters to the right of the text.
+The first argument is the character to be
 printed, and the second argument is the distance away from the main body
 text.  With no arguments the margin characters are turned off.  If this
-occurs before a break, no margin character will be printed.
+occurs before a break, no margin character is printed.
 
 @pindex nrchbar
 @pindex changebar
@@ -7353,146 +8587,218 @@ there are programs available for doing this (they are called
 @c XXX example
 
 @ignore
-@example
+@Example
 ... margin char example ...
-@end example
+@endExample
 @end ignore
+@endDefreq
 
-@findex lf
 @pindex soelim
 @cindex multi-file documents
 @cindex documents, multi-file
-The primary reason for the existence of @code{lf} is to make debugging
-documents which are split into many files, which are then put together
-with @code{soelim} and other preprocessors.  The first argument is the
-name of the file and the second argument is the input line number in
+@Defreq {lf, line filename}
+A debugging aid for
+documents which are split into many files, then put together
+with @code{soelim} and other preprocessors.  The second argument is the
+name of the file and the first argument is the input line number in
 that file.  This way @code{gtroff} can produce error messages which are
 intelligible to the user.
 
 @c XXX example
 
 @ignore
-@example
+@Example
 ... example of soelim'ed doc ...
-@end example
+@endExample
 @end ignore
+@endDefreq
+
+
+@c =====================================================================
+
+@node Gtroff Internals, Debugging, Miscellaneous, gtroff Reference
+@section @code{gtroff} Internals
+
+@cindex input token
+@cindex token, input
+@cindex output node
+@cindex node, output
+@code{gtroff} processes input in three steps.  One or more input
+characters are converted to an @dfn{input token}.  Then, one or more
+input tokens are converted to an @dfn{output node}.  Finally, output
+nodes are converted to the intermediate output language understood by
+all output devices.
+
+For example, the input string @samp{fi\[:u]} is converted in a
+character token @samp{f}, a character token @samp{i}, and a special
+token @samp{:u} (representing u@w{ }umlaut).  Later on, the character
+tokens @samp{f} and @samp{i} are merged to a single output node
+representing the ligature glyph @samp{fi}; the same happens with
+@samp{:u}.  All output glyph nodes are `processed' which means that
+they are invariably associated with a given font, font size, advance
+width, etc.  During the formatting process, @code{gtroff} itself adds
+various nodes to control the data flow.
+
+Macros, diversions, and strings collect elements in two chained lists:
+a list of input tokens which have been passed unprocessed, and a list
+of output nodes.  Consider the following the diversion.
+
+@Example
+.di xxx
+a
+\!b
+c
+.br
+.di
+@endExample
+
+@noindent
+It contains these elements.
+
+@multitable {@i{vertical size node}} {token list} {element number}
+@item node list               @tab token list @tab element number
+
+@item @i{line start node}     @tab ---        @tab 1
+@item @i{glyph node @code{a}} @tab ---        @tab 2
+@item @i{word space node}     @tab ---        @tab 3
+@item ---                     @tab @code{b}   @tab 4
+@item ---                     @tab @code{\n}  @tab 5
+@item @i{glyph node @code{c}} @tab ---        @tab 6
+@item @i{vertical size node}  @tab ---        @tab 7
+@item @i{vertical size node}  @tab ---        @tab 8
+@item ---                     @tab @code{\n}  @tab 9
+@end multitable
+
+@esindex \v
+@rqindex unformat
+@noindent
+Elements 1, 7, and@w{ }8 are inserted by @code{gtroff}; the latter two
+(which are always present) specify the vertical extent of the last
+line, possibly modified by @code{\v}.  The @code{br} request finishes
+the current partial line, inserting a newline input token which is
+subsequently converted to a space when the diversion is reread.  Note
+that the word space node has a fixed width which isn't stretchable
+anymore.  To convert horizontal space nodes back to input tokens, use
+the @code{unformat} request.
+
+Macros only contain elements in the token list (and the node list is
+empty); diversions and strings can contain elements in both lists.
 
 
 @c =====================================================================
 
-@node Debugging, Implementation Differences, Miscellaneous, Programming Tutorial
+@node Debugging, Implementation Differences, Gtroff Internals, gtroff Reference
 @section Debugging
 @cindex debugging
 
 @code{gtroff} is not easy to debug, but there are some useful features
 and strategies for debugging.
 
-@itemize @bullet
-@item
-@findex tm
-The @code{tm} request will send output to the standard error stream;
-this is very useful for printing debugging output.
+@Defreq {tm, string}
+Sends the @var{string} to the standard error stream;
+this is very useful for printing debugging output among other things.
+@endDefreq
+
+@cindex aborting
+@Defreq {ab, [@Var{string}]}
+Similar to the @code{tm} request, except that
+it causes @code{gtroff} to stop processing.  With no argument it
+prints @samp{User Abort}.
+@endDefreq
+
+@cindex @code{ex}, use in debugging
+@cindex exiting
+@Defreq {ex, }
+The @code{ex} request also causes @code{gtroff} to stop processing
+if encountered at the topmost level; see also @ref{I/O}.
+@endDefreq
 
-@item
 When doing something involved it is useful to leave the debugging
 statements in the code and have them turned on by a command line flag.
 
-@example
+@Example
 .if \n(DB .tm debugging output
-@end example
+@endExample
 
 @noindent
 To activate these statements say
 
-@example
+@Example
 groff -rDB=1 file
-@end example
-
-@item
-@findex ab
-@cindex aborting
-The @code{ab} request is similar to the @code{tm} request, except that
-it will cause @code{gtroff} to stop processing.  With no argument it
-will print @samp{User Abort}.
+@endExample
 
-@item
-@findex ex@r{, use in debugging}
-@cindex exiting
-The @code{ex} request will also cause @code{gtroff} to stop processing
-if encountered at the topmost level; see also @ref{I/O}.
+@c XXX .tm1, .tmc requests
 
-@item
 If it is known in advance that there will be many errors and no useful
 output, @code{gtroff} can be forced to suppress formatted output with
 the @option{-z} flag.
 
-@item
-@findex pm
 @cindex dumping symbol table
 @cindex symbol table, dumping
-The @code{pm} request will dump out the entire symbol table.
+@Defreq {pm, }
+The @code{pm} request prints out the entire symbol table on @code{stderr}.
+@endDefreq
 
-@item
-@findex pnr
 @cindex dumping number registers
 @cindex number registers, dumping
-The @code{pnr} request will print the names and contents of all
-currently defined number registers on stderr.
+@Defreq {pnr, }
+Prints the names and contents of all
+currently defined number registers on @code{stderr}.
+@endDefreq
 
-@item
-@findex ptr
 @cindex dumping traps
 @cindex traps, dumping
-The @code{ptr} request will print the names and positions of all traps
-(not including input line traps and diversion traps) on stderr.  Empty
-slots in the page trap list are printed as well, because they can affect
-the priority of subsequently planted traps.
+@Defreq {ptr, }
+Prints the names and positions of all traps
+(not including input line traps and diversion traps) on @code{stderr}.
+Empty slots in the page trap list are printed as well, because they can
+affect the priority of subsequently planted traps.
+@endDefreq
 
-@item
-@findex fl
 @cindex flush output
 @cindex output, flush
 @cindex interactive use of @code{gtroff}
 @cindex @code{gtroff}, interactive use
-The @code{fl} request instructs @code{gtroff} to flush its output
-immediately.  The intention is that this be used when using
-@code{gtroff} interactively.  There is little other use for it.  This
+@Defreq {fl, }
+Instructs @code{gtroff} to flush its output
+immediately.  The intent is for interactive use.
+@code{gtroff}; there is little other use for it.  This
 request causes a line break.
+@endDefreq
 
-@item
-@findex backtrace
 @cindex backtrace of input stack
 @cindex input stack, backtrace
-The @code{backtrace} request will print a backtrace of the input stack
+@Defreq {backtrace, }
+The @code{backtrace} request prints a backtrace of the input stack
 to the standard error stream.
+@endDefreq
 
-@item
 @cindex warnings
 @code{gtroff} has command line options for printing out more warnings
 (@option{-w}) and for printing backtraces (@option{-b}) when a warning
 or an error occurs.  The most verbose level of warnings is @option{-ww}.
 
-@item
-@findex warn
-@vindex .warn
 @cindex level of warnings
 @cindex warnings, level
-The @code{warn} request controls the level of warnings checked for.  The
-only argument is the sum of the numbers associated with each warning
-that is to be enabled; all other warnings will be disabled.  The number
-associated with each warning is listed below.  For example,
-@w{@code{.warn 0}} will disable all warnings, and @w{@code{.warn 1}}
-will disable all warnings except that about missing characters.  If an
-argument is not given, all warnings will be enabled.  The number
-register @code{.warn} contains the current warning level.
-@end itemize
-
-@c ---------------------------------------------------------------------
+@Defreq {warn, [@Var{flags}]}
+@Defregx {.warn}
+Controls the level of warnings checked for.  The @var{flags} are the sum
+of the numbers associated with each warning that is to be enabled; all
+other warnings are disabled.  The number associated with each warning is
+listed below.  For example, @w{@code{.warn 0}} disables all warnings,
+and @w{@code{.warn 1}} disables all warnings except that about missing
+characters.  If an argument is not given, all warnings are enabled.
+
+The read-only number register @code{.warn} contains the current warning
+level.
+@endDefreq
 
 @menu
-* Warnings::                    
+* Warnings::
 @end menu
 
+@c ---------------------------------------------------------------------
+
 @node Warnings,  , Debugging, Debugging
 @subsection Warnings
 @cindex warnings
@@ -7525,8 +8831,8 @@ Missing or mismatched closing delimiters.
 
 @item el
 @itemx 16
-@findex ie
-@findex el
+@rqindex ie
+@rqindex el
 Use of the @code{el} request with no matching @code{ie} request.
 @xref{if-else}.
 
@@ -7544,28 +8850,30 @@ Dubious syntax in numeric expressions.
 
 @item di
 @itemx 256
-@findex di@r{, debugging}
-@findex da@r{, debugging}
+@rqindex di
+@rqindex da
+@cindex @code{di}, debugging
+@cindex @code{da}, debugging
 Use of @code{di} or @code{da} without an argument when there is no
 current diversion.
 
 @item mac
 @itemx 512
-@findex de
-@c XXX more findex entries
+@rqindex de
+@c XXX more index entries
 Use of undefined strings, macros and diversions.  When an undefined
 string, macro or diversion is used, that string is automatically defined
-as empty.  So, in most cases, at most one warning will be given for each
+as empty.  So, in most cases, at most one warning is given for each
 name.
 
 @item  reg
 @itemx 1024
-@findex nr
-@c XXX more findex entries
+@rqindex nr
+@c XXX more index entries
 Use of undefined number registers.  When an undefined number register is
 used, that register is automatically defined to have a value of@w{ }0.
 A definition is automatically made with a value of@w{ }0.  So, in most
-cases, at most one warning will be given for use of a particular name.
+cases, at most one warning is given for use of a particular name.
 
 @item  tab
 @itemx 2048
@@ -7573,7 +8881,8 @@ Use of a tab character where a number was expected.
 
 @item  right-brace
 @itemx 4096
-@findex \@}@r{, debugging}
+@esindex \@}
+@cindex @code{\@}}, debugging
 Use of @code{\@}} where a number was expected.
 
 @item  missing
@@ -7593,11 +8902,11 @@ encountered, the escape character is ignored.
 @itemx 65536
 @cindex compatibility mode
 Missing space between a request or macro and its argument.  This warning
-will be given when an undefined name longer than two characters is
+is given when an undefined name longer than two characters is
 encountered, and the first two characters of the name make a defined
-name.  The request or macro will not be invoked.  When this warning is
+name.  The request or macro is not invoked.  When this warning is
 given, no macro is automatically defined.  This is enabled by default.
-This warning will never occur in compatibility mode.
+This warning never occurs in compatibility mode.
 
 @item  font
 @itemx 131072
@@ -7615,7 +8924,7 @@ All warnings.
 
 @c =====================================================================
 
-@node Implementation Differences, Summary, Debugging, Programming Tutorial
+@node Implementation Differences, Summary, Debugging, gtroff Reference
 @section Implementation Differences
 @cindex implementation differences
 @cindex differences in implementation
@@ -7629,46 +8938,48 @@ with documents written with old versions of @code{troff}.
 @cindex long names
 @cindex names, long
 Long names cause some incompatibilities.  @acronym{UNIX} @code{troff}
-will interpret
+interprets
 
-@example
+@Example
 .dsabcd
-@end example
+@endExample
 
-@findex \*@r{, incompatibilities with Unix @code{troff}}
-@findex \n@r{, incompatibilities with Unix @code{troff}}
-@findex cp
+@esindex \*
+@esindex \n
+@cindex @code{\*}, incompatibilities with Unix @code{troff}
+@cindex @code{\n}, incompatibilities with Unix @code{troff}
+@rqindex cp
 @vindex .C
 @noindent
 as defining a string @samp{ab} with contents @samp{cd}.  Normally, GNU
-@code{troff} will interpret this as a call of a macro named
-@code{dsabcd}.  Also @acronym{UNIX} @code{troff} will interpret
+@code{troff} interprets this as a call of a macro named
+@code{dsabcd}.  Also @acronym{UNIX} @code{troff} interprets
 @code{\*[} or @code{\n[} as references to a string or number register
-called @samp{[}.  In GNU @code{troff}, however, this will normally be
+called @samp{[}.  In GNU @code{troff}, however, this is normally
 interpreted as the start of a long name.  In compatibility mode GNU
-@code{troff} will interpret these things in the traditional way.  In
-compatibility mode, however, long names are not recognized.
+@code{troff} interprets long names in the traditional way
+(which means that they are not recognized as names).
 Compatibility mode can be turned on with the @option{-C} command line
 option, and turned on or off with the @code{cp} request.  The number
 register @code{.C} is@w{ }1 if compatibility mode is on, 0@w{
 }otherwise.
 
-@findex \A
-@findex \|
-@findex \^
-@findex \&
-@findex \@}
-@findex \@{
-@findex \@key{SP}
-@findex \'
-@findex \`
-@findex \-
-@findex \_
-@findex \!
-@findex \%
-@findex \c
+@esindex \A
+@esindex \|
+@esindex \^
+@esindex \&
+@esindex \@{
+@esindex \@}
+@esindex \@key{SP}
+@esindex \'
+@esindex \`
+@esindex \-
+@esindex \_
+@esindex \!
+@esindex \%
+@esindex \c
 GNU @code{troff} does not allow the use of the escape sequences
-@code{\|}, @code{\^}, @code{\&}, @code{\@}}, @code{\@{},
+@code{\|}, @code{\^}, @code{\&}, @code{\@{}, @code{\@}},
 @code{\@key{SP}}, @code{\'}, @code{\`}, @code{\-}, @code{\_}, @code{\!},
 @code{\%}, and @code{\c} in names of strings, macros, diversions, number
 registers, fonts or environments; @acronym{UNIX} @code{troff} does.  The
@@ -7677,31 +8988,37 @@ avoiding use of these escape sequences in names.
 
 @cindex fractional point sizes
 @cindex point sizes, fractional
-@findex ps@r{, incompatibilities with Unix @code{troff}}
+@rqindex ps
+@cindex @code{ps}, incompatibilities with Unix @code{troff}
 Fractional point sizes cause one noteworthy incompatibility.  In
 @acronym{UNIX} @code{troff} the @code{ps} request ignores scale
 indicators and thus
 
-@example
+@Example
 .ps 10u
-@end example
+@endExample
 
 @noindent
-will set the point size to 10@w{ }points, whereas in GNU @code{troff} it
-will set the point size to 10@w{ }scaled points.  @xref{Fractional Type
+sets the point size to 10@w{ }points, whereas in GNU @code{troff} it
+sets the point size to 10@w{ }scaled points.  @xref{Fractional Type
 Sizes}, for more information.
 
-@findex bd@r{, incompatibilities with Unix @code{troff}}
-@findex cs@r{, incompatibilities with Unix @code{troff}}
-@findex tkf@r{, incompatibilities with Unix @code{troff}}
-@findex tr@r{, incompatibilities with Unix @code{troff}}
-@findex fp@r{, incompatibilities with Unix @code{troff}}
+@rqindex bd
+@rqindex cs
+@rqindex tkf
+@rqindex tr
+@rqindex fp
+@cindex @code{bd}, incompatibilities with Unix @code{troff}
+@cindex @code{cs}, incompatibilities with Unix @code{troff}
+@cindex @code{tkf}, incompatibilities with Unix @code{troff}
+@cindex @code{tr}, incompatibilities with Unix @code{troff}
+@cindex @code{fp}, incompatibilities with Unix @code{troff}
 @cindex input and output characters, compatibility with Unix
 @cindex output characters, compatibility with Unix
 @cindex characters, input and output, compatibility with Unix
 In GNU @code{troff} there is a fundamental difference between
 unformatted, input characters, and formatted, output characters.
-Everything that affects how an output character will be output is stored
+Everything that affects how an output character is output is stored
 with the character; once an output character has been constructed it is
 unaffected by any subsequent requests that are executed, including
 @code{bd}, @code{cs}, @code{tkf}, @code{tr}, or @code{fp} requests.
@@ -7714,40 +9031,46 @@ character for the purposes of macro processing; it does not inherit any
 of the special properties that the input character from which it was
 constructed might have had.  For example,
 
-@example
+@Example
 .di x
 \\\\
 .br
 .di
 .x
-@end example
-
-@findex \e@r{, incompatibilities with Unix @code{troff}}
-@findex \!@r{, incompatibilities with Unix @code{troff}}
-@findex \?@r{, incompatibilities with Unix @code{troff}}
+@endExample
+
+@esindex \e
+@esindex \!
+@esindex \?
+@cindex @code{\e}, incompatibilities with Unix @code{troff}
+@cindex @code{\!}, incompatibilities with Unix @code{troff}
+@cindex @code{\?}, incompatibilities with Unix @code{troff}
 @cindex transparent output, incompatibilities with Unix @code{troff}
 @cindex output, transparent, incompatibilities with Unix @code{troff}
 @noindent
-will print @samp{\\} in GNU @code{troff}; each pair of input backslashes
+prints @samp{\\} in GNU @code{troff}; each pair of input backslashes
 is turned into one output backslash and the resulting output backslashes
 are not interpreted as escape characters when they are reread.
 @acronym{UNIX} @code{troff} would interpret them as escape characters
 when they were reread and would end up printing one @samp{\}.  The
 correct way to obtain a printable backslash is to use the @code{\e}
-escape sequence: This will always print a single instance of the current
+escape sequence: This always prints a single instance of the current
 escape character, regardless of whether or not it is used in a
-diversion; it will also work in both GNU @code{troff} and @acronym{UNIX}
+diversion; it also works in both GNU @code{troff} and @acronym{UNIX}
 @code{troff}.  To store, for some reason, an escape sequence in a
 diversion that will be interpreted when the diversion is reread, either
 use the traditional @code{\!} transparent output facility, or, if this
 is unsuitable, the new @code{\?} escape sequence.
 
+@c XXX .tl compatibility mode -> input stack level
+@c XXX .if compatibility mode -> input stack level
+
 @xref{Diversions}, for more information.
 
 
 @c =====================================================================
 
-@node Summary,  , Implementation Differences, Programming Tutorial
+@node Summary,  , Implementation Differences, gtroff Reference
 @section Summary
 @cindex summary
 
@@ -7758,7 +9081,7 @@ is unsuitable, the new @code{\?} escape sequence.
 @c =====================================================================
 @c =====================================================================
 
-@node Preprocessors, Output Devices, Programming Tutorial, Top
+@node Preprocessors, Output Devices, gtroff Reference, Top
 @chapter Preprocessors
 @cindex preprocessors
 
@@ -7766,13 +9089,13 @@ This chapter describes all preprocessors that come with @code{groff} or
 which are freely available.
 
 @menu
-* geqn::                        
-* gtbl::                        
-* gpic::                        
-* ggrn::                        
-* grap::                        
-* grefer::                      
-* gsoelim::                     
+* geqn::
+* gtbl::
+* gpic::
+* ggrn::
+* grap::
+* grefer::
+* gsoelim::
 @end menu
 
 
@@ -7786,7 +9109,7 @@ which are freely available.
 @c XXX
 
 @menu
-* Invoking geqn::               
+* Invoking geqn::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -7809,7 +9132,7 @@ which are freely available.
 @c XXX
 
 @menu
-* Invoking gtbl::               
+* Invoking gtbl::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -7832,7 +9155,7 @@ which are freely available.
 @c XXX
 
 @menu
-* Invoking gpic::               
+* Invoking gpic::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -7855,7 +9178,7 @@ which are freely available.
 @c XXX
 
 @menu
-* Invoking ggrn::               
+* Invoking ggrn::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -7892,7 +9215,7 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* Invoking grefer::             
+* Invoking grefer::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -7915,7 +9238,7 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* Invoking gsoelim::            
+* Invoking gsoelim::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -7940,14 +9263,14 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* Special Characters::          
-* grotty::                      
-* grops::                       
-* grodvi::                      
-* grolj4::                      
-* grolbp::                      
-* grohtml::                     
-* gxditview::                   
+* Special Characters::
+* grotty::
+* grops::
+* grodvi::
+* grolj4::
+* grolbp::
+* grohtml::
+* gxditview::
 @end menu
 
 
@@ -7972,7 +9295,7 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* Invoking grotty::             
+* Invoking grotty::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -7994,8 +9317,8 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* Invoking grops::              
-* Embedding PostScript::        
+* Invoking grops::
+* Embedding PostScript::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -8026,7 +9349,7 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* Invoking grodvi::             
+* Invoking grodvi::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -8048,7 +9371,7 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* Invoking grolj4::             
+* Invoking grolj4::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -8070,7 +9393,7 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* Invoking grolbp::             
+* Invoking grolbp::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -8092,7 +9415,7 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* Invoking grohtml::            
+* Invoking grohtml::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -8114,7 +9437,7 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* Invoking gxditview::          
+* Invoking gxditview::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -8140,8 +9463,8 @@ is available as an extra package from the following address:
 @c XXX
 
 @menu
-* gtroff Output::               
-* Font Files::                  
+* gtroff Output::
+* Font Files::
 @end menu
 
 
@@ -8153,14 +9476,15 @@ is available as an extra package from the following address:
 @cindex output, @code{gtroff}
 
 This section describes the format output of GNU @code{troff}.  The
-output format used by GNU @code{troff} is very similar to that used by
+output format used by GNU @code{troff} is very similar -- but
+not identical -- to that used by
 @acronym{UNIX} device-independent @code{troff} (@code{ditroff}).
 
 @menu
-* Output Format::               
-* Device Control::              
-* Drawing Functions::           
-* Line Continuation::           
+* Output Format::
+* Device Control::
+* Drawing Functions::
+* Line Continuation::
 @end menu
 
 @c ---------------------------------------------------------------------
@@ -8182,10 +9506,10 @@ parameters which are separated from subsequent text by whitespace or a
 newline.
 
 The names of characters and fonts can be of arbitrary length; drivers
-should not assume that they will be only two characters long (as
+should not assume that they are only two characters long (as
 @code{ditroff} does).
 
-When a character is to be printed, that character will always be in the
+When a character is to be printed, that character is always in the
 current font.  Unlike @code{ditroff}, it is not necessary for drivers to
 search special fonts to find a character.
 
@@ -8286,28 +9610,28 @@ points.
 
 The first three output commands are guaranteed to be:
 
-@example
+@Example
 x T device
 x res n h v
 x init
-@end example
+@endExample
 
 @noindent
 For example, the input
 
-@example
+@Example
 crunchy \fH\s+2frog\s0\fP!?
-@end example
+@endExample
 
 @noindent
-will produce
+produces
 
 @c XXX example
 
 @ignore
-@example
+@Example
 ... sample output here ...
-@end example
+@endExample
 @end ignore
 
 @c ---------------------------------------------------------------------
@@ -8318,8 +9642,8 @@ will produce
 @cindex functions for drawing
 
 @pindex gpic
-The @samp{D} drawing command has been extended.  These extensions will
-only be used by GNU @code{pic} if the @option{-x} option is given.
+The @samp{D} drawing command has been extended.  These extensions are
+used by GNU @code{pic} only if the @option{-x} option is given.
 
 @xref{Drawing Requests}.
 
@@ -8331,11 +9655,11 @@ Set the shade of gray to be used for filling solid objects to@w{
 corresponds solid white and 1000 to solid black, and values in between
 correspond to intermediate shades of gray.  This applies only to solid
 circles, solid ellipses and solid polygons.  By default, a level of@w{
-}1000 will be used.  Whatever color a solid object has, it should
+}1000 is used.  Whatever color a solid object has, it should
 completely obscure everything beneath it.  A value greater than@w{ }1000
 or less than@w{ }0 can also be used: this means fill with the shade of
 gray that is currently being used for lines and text.  Normally this
-will be black, but some drivers may provide a way of changing this.
+is black, but some drivers may provide a way of changing this.
 
 @item DC @var{d}
 Draw a solid circle with a diameter of@w{ }@var{d} with the leftmost
@@ -8347,11 +9671,12 @@ vertical diameter of@w{ }@var{dy} with the leftmost point at the current
 position.
 
 @item Dp @var{dx1} @var{dy1} @var{dx2} @var{dy2} @dots{} @var{dxn} @var{dyn}
-Draw a polygon with.  The first vertex is at the current position, the
-second vertex at an offset (@var{dx1},@var{dy1}) from the current
-position, the second vertex at an offset (@var{dx2},@var{dy2}) from the
-first vertex, and so on up to the @var{n}-th vertex.  At the moment, GNU
-@code{pic} only uses this command to generate triangles and rectangles.
+Draw a polygon with automatic closure.  The first vertex is at the
+current position, the second vertex at an offset (@var{dx1},@var{dy1})
+from the current position, the second vertex at an offset
+(@var{dx2},@var{dy2}) from the first vertex, and so on up to the
+@var{n}@dmn{th} vertex.  At the moment, GNU @code{pic} only uses this
+command to generate triangles and rectangles.
 
 @item DP @var{dx1} @var{dy1} @var{dx2} @var{dy2} @dots{} @var{dxn} @var{dyn}
 Like @code{Dp} but draw a solid rather than outlined polygon.
@@ -8367,24 +9692,24 @@ has been given with a negative value of@w{ }@var{n}.  A zero value of@w{
 }@var{n} selects the smallest available line thickness.
 @end table
 
-@findex \D
+@esindex \D
 A difficulty arises in how the current position should be changed after
 the execution of these commands.  This is not of great importance since
 the code generated by GNU @code{pic} does not depend on this.  Given a
 drawing command of the form
 
-@example
+@Example
 \D'@var{c} @var{x1} @var{y1} @var{x2} @var{y2} @dots{} @var{xn} @var{yn}'
-@end example
+@endExample
 
-@findex \w
+@esindex \w
 @vindex st
-@findex sb
+@vindex sb
 @noindent
 where @var{c} is not one of @samp{c}, @samp{e}, @samp{l}, @samp{a} or
-@samp{~}, @acronym{UNIX} @code{troff} will treat each of the x@w{ }value
-as a horizontal quantity, and each of the y@w{ }values as a vertical
-quantity and will assume that the width of the drawn object is sum if
+@samp{~}, @acronym{UNIX} @code{troff} treats each x@w{ }value
+as a horizontal quantity, and each y@w{ }value as a vertical
+quantity; it assumes that the width of the drawn object is the sum of
 all x@w{ }values, and that the height is the sum of all y@w{ }values.
 (The assumption about the height can be seen by examining the @code{st}
 and @code{sb} registers after using such a @code{D}@w{ }command in a
@@ -8395,9 +9720,9 @@ produces an ugly result in the case of the @code{Df}, @code{Dt}, and, to
 a lesser extent, @code{DE}@w{ }commands.  Thus after executing a
 @code{D}@w{ }command of the form
 
-@example
+@Example
 D@var{c} @var{x1} @var{y1} @var{x2} @var{y2} @dots{} @var{xn} @var{yn}
-@end example
+@endExample
 
 @noindent
 the current position should be increased horizontally by the sum of all
@@ -8412,8 +9737,8 @@ x@w{ }values and vertically by the sum of all y@w{ }values.
 
 There is a continuation convention which permits the argument to the
 @w{@samp{x X}} command to contain newlines: When outputting the argument
-to the @w{@samp{x X}} command, GNU @code{troff} will follow each newline
-in the argument with a @samp{+} character (as usual, it will terminate
+to the @w{@samp{x X}} command, GNU @code{troff} follows each newline
+in the argument with a @samp{+} character (as usual, it terminates
 the entire argument with a newline); thus if the line after the line
 containing the @w{@samp{x X}} command starts with @samp{+}, then the
 newline ending the line containing the @w{@samp{x X}} command should be
@@ -8439,14 +9764,14 @@ file called @file{DESC} and for each font@w{ }@var{f} a font file
 called@w{ }@file{@var{f}}.
 
 @menu
-* DESC file format::            
-* Font file format::            
+* DESC File Format::
+* Font File Format::
 @end menu
 
 @c ---------------------------------------------------------------------
 
-@node DESC file format, Font file format, Font Files, Font Files
-@subsection @file{DESC} file format
+@node DESC File Format, Font File Format, Font Files, Font Files
+@subsection @file{DESC} File Format
 @cindex @file{DESC} file format
 @cindex font description file format
 @cindex format of font description file
@@ -8493,16 +9818,15 @@ list can extend over more than one line.
 
 @item styles @var{S1} @var{S2} @dots{} @var{Sm}
 @kindex styles
-The first @var{m}@w{ }font positions will be associated with styles
+The first @var{m}@w{ }font positions are associated with styles
 @var{S1} @dots{} @var{Sm}.
 
 @item fonts @var{n} @var{F1} @var{F2} @var{F3} @dots{} @var{Fn}
 @kindex fonts
-Fonts @var{F1} @dots{} @var{Fn} will be mounted in the font positions
+Fonts @var{F1} @dots{} @var{Fn} are mounted in the font positions
 @var{m}+1, @dots{}, @var{m}+@var{n} where @var{m} is the number of
 styles.  This command may extend over more than one line.  A font name
-of@var{ }0 will cause no font to be mounted on the corresponding font
-position.
+of@var{ }0 means no font is mounted on the corresponding font position.
 
 @item family @var{fam}
 @kindex family
@@ -8524,8 +9848,8 @@ in the @file{DESC} file.
 
 @c ---------------------------------------------------------------------
 
-@node Font file format,  , DESC file format, Font Files
-@subsection Font file format
+@node Font File Format,  , DESC File Format, Font Files
+@subsection Font File Format
 @cindex font file format
 @cindex format of font files
 
@@ -8558,7 +9882,7 @@ than one line.
 @item special
 @kindex special
 The font is special; this means that when a character is requested that
-is not present in the current font, it will be searched for in any
+is not present in the current font, it is searched for in any
 special fonts that are mounted.
 @end table
 
@@ -8585,13 +9909,13 @@ separated by blanks or tabs.  The format is
 
 @c XXX fix it for new HTML additions
 
-@example
+@Example
 @var{name} @var{metrics} @var{type} @var{code} @var{comment}
-@end example
+@endExample
 
 @cindex 8-bit input
 @cindex input, 8-bit
-@findex \N
+@esindex \N
 @kindex ---
 @noindent
 @var{name} identifies the character: If @var{name} is a single
@@ -8628,18 +9952,18 @@ the character has both an ascender and a descender, for example, `('.
 The @var{code} field gives the code which the postprocessor uses to
 print the character.  The character can also be input to @code{gtroff}
 using this code by means of the @code{\N} escape sequence.  The code can
-be any integer.  If it starts with @samp{0} it will be interpreted as
-octal; if it starts with @samp{0x} or @samp{0X} it will be interpreted as
+be any integer.  If it starts with @samp{0} it is interpreted as
+octal; if it starts with @samp{0x} or @samp{0X} it is interpreted as
 hexadecimal.
 
-Anything on the line after the @var{code} field will be ignored.
+Anything on the line after the @var{code} field is ignored.
 
 The @var{metrics} field has the form:
 
-@example
+@Example
 @var{width}[,@var{height}[,@var{depth}[,@var{italic_correction}
   [,@var{left_italic_correction}[,@var{subscript_correction}]]]]]
-@end example
+@endExample
 
 @noindent
 There must not be any spaces between these subfields (it has been split
@@ -8657,19 +9981,19 @@ the lowest point below the baseline to which the character extends
 baseline, it should be given a zero depth, rather than a negative depth.
 The @var{italic_correction} subfield gives the amount of space that
 should be added after the character when it is immediately to be
-followed by a character from a Roman font.  The
+followed by a character from a roman font.  The
 @var{left_italic_correction} subfield gives the amount of space that
 should be added before the character when it is immediately to be
-preceded by a character from a Roman font.  The
+preceded by a character from a roman font.  The
 @var{subscript_correction} gives the amount of space that should be
 added after a character before adding a subscript.  This should be less
 than the italic correction.
 
 A line in the @code{charset} section can also have the format
 
-@example
+@Example
 @var{name} "
-@end example
+@endExample
 
 @noindent
 This indicates that @var{name} is just another name for the character
@@ -8679,13 +10003,14 @@ mentioned in the preceding line.
 The word @code{kernpairs} starts the kernpairs section.  This contains a
 sequence of lines of the form:
 
-@example
+@Example
 @var{c1} @var{c2} @var{n}
-@end example
+@endExample
 
+@noindent
 This means that when character @var{c1} appears next to character
 @var{c2} the space between them should be increased by@w{ }@var{n}.
-Most entries in kernpairs section will have a negative value for@w{
+Most entries in the kernpairs section have a negative value for@w{
 }@var{n}.
 
 
@@ -8693,7 +10018,7 @@ Most entries in kernpairs section will have a negative value for@w{
 @c =====================================================================
 @c =====================================================================
 
-@node Installation, Request and Escape Index, File formats, Top
+@node Installation, Request Index, File formats, Top
 @chapter Installation
 @cindex installation
 
@@ -8704,21 +10029,30 @@ Most entries in kernpairs section will have a negative value for@w{
 @c =====================================================================
 @c =====================================================================
 
-@node Request and Escape Index, Operator Index, Installation, Top
-@chapter Request and Escape Index
+@node Request Index, Escape Index, Installation, Top
+@chapter Request Index
 
-In this index, escapes are listed with a leading backslash (@samp{\}) to
-distinguish them from requests which appear without the leading control
-character (normally either @samp{.} or @samp{'}).
+Requests appear without the leading control character (normally either
+@samp{.} or @samp{'}).
 
-@printindex fn
+@printindex rq
 
 
 
 @c =====================================================================
 @c =====================================================================
 
-@node Operator Index, Register Index, Request and Escape Index, Top
+@node Escape Index, Operator Index, Request Index, Top
+@chapter Escape Index
+
+@printindex es
+
+
+
+@c =====================================================================
+@c =====================================================================
+
+@node Operator Index, Register Index, Escape Index, Top
 @chapter Operator Index
 
 @printindex op
@@ -8728,7 +10062,7 @@ character (normally either @samp{.} or @samp{'}).
 @c =====================================================================
 @c =====================================================================
 
-@node Register Index, Macro and String Index, Operator Index, Top
+@node Register Index, Macro Index, Operator Index, Top
 @chapter Register Index
 
 @printindex vr
@@ -8738,12 +10072,8 @@ character (normally either @samp{.} or @samp{'}).
 @c =====================================================================
 @c =====================================================================
 
-@node Macro and String Index, Glyph Name Index, Register Index, Top
-@chapter Macro and String Index
-
-In this index, strings are listed with the calling escape sequence
-(@samp{\*}) to distinguish them from macros which appear without the
-leading control character (normally either @samp{.} or @samp{'}).
+@node Macro Index, String Index, Register Index, Top
+@chapter Macro Index
 
 @printindex ma
 
@@ -8752,7 +10082,17 @@ leading control character (normally either @samp{.} or @samp{'}).
 @c =====================================================================
 @c =====================================================================
 
-@node Glyph Name Index, Font File Keyword Index, Macro and String Index, Top
+@node String Index, Glyph Name Index, Macro Index, Top
+@chapter String Index
+
+@printindex st
+
+
+
+@c =====================================================================
+@c =====================================================================
+
+@node Glyph Name Index, Font File Keyword Index, String Index, Top
 @chapter Glyph Name Index
 
 A glyph name @code{xx} consisting of exactly two characters can be
diff --git a/contrib/groff/doc/homepage.ms b/contrib/groff/doc/homepage.ms
index b542d73..00da216 100644
--- a/contrib/groff/doc/homepage.ms
+++ b/contrib/groff/doc/homepage.ms
@@ -2,9 +2,9 @@
 .\" with groff.
 .\"
 .\"
-.\" To make it work with other output devices also, we include tmac.arkup
+.\" To make it work with other output devices also, we include arkup.tmac
 .\" directly.
-.mso tmac.arkup
+.mso arkup.tmac
 .\"
 .LP
 .\"
@@ -139,16 +139,18 @@ bug-groff@gnu.org      for reporting bugs
 groff@gnu.org          for general discussion of groff
 groff-commit@ffii.org  a read-only list showing logs of
                        commitments to the CVS repository
-\fR
+\fP
 .fi
 .RE
 .sp
 .LP
-Note that groff@gnu.org is an alias for groff@ffii.org; you must be
-subscribed to the `groff' and `groff-commit' lists to send mails.
+Note that groff@gnu.org is an alias for
+.MAILTO groff@ffii.org groff@ffii.org ;
+you must be subscribed to the `groff' and `groff-commit' lists to send mails.
 .LP
 To subscribe, send e-mail to [list]-request@[domain] (example:
-groff-request@ffii.org) with the word `subscribe' in either the
+.MAILTO groff-request@ffii.org groff-request@ffii.org )
+with the word `subscribe' in either the
 subject or body of the e-mail (don't include the quotes).
 .LP
 GNU groff was written by
@@ -157,6 +159,6 @@ It is now maintained by
 .MAILTO Ted.Harding@nessie.mcc.ac.uk "Ted Harding"
 and
 .MAILTO wl@gnu.org "Werner Lemberg" .
-.LINE
+.br
 .
 .\" EOF
diff --git a/contrib/groff/doc/meref.me b/contrib/groff/doc/meref.me
index 445fcd7..e99bfd0 100644
--- a/contrib/groff/doc/meref.me
+++ b/contrib/groff/doc/meref.me
@@ -1271,7 +1271,7 @@ is spread or broken (including hyphenated).
 In other words,
 it is safe in nofill mode only.
 .TL
-.b sm
+.b .sm
 .i W
 .i X
 .DE
@@ -2021,7 +2021,7 @@ NAME	TYPE	DESCRIPTION
 \e0	F\(sc	unpaddable digit-width space
 \&.1c	M	revert to single column output
 \&.2c	M	begin two column output
-\e*:	S	umlat
+\e*:	S	umlaut
 \e*<	S	begin subscript
 \e*>	S	end subscript
 \&.EN	M	end equation
diff --git a/contrib/groff/doc/pic.ms b/contrib/groff/doc/pic.ms
index 8553953..a38d58f 100644
--- a/contrib/groff/doc/pic.ms
+++ b/contrib/groff/doc/pic.ms
@@ -10,7 +10,7 @@
 .\" This document was written for free use and redistribution by
 .\" Eric S. Raymond <esr@thyrsus.com> in August 1995.
 .\"
-.\"	$Id: pic.ms,v 1.1.1.1 2000/02/06 09:39:20 wlemb Exp $	
+.\"	$Id: pic.ms,v 1.3 2001/04/13 17:11:32 wlemb Exp $	
 .\"
 .\" Set a proper TeX
 .ie t .ds tx T\h'-.1667m'\v'.224m'E\v'-.224m'\h'-.125m'X
@@ -806,7 +806,7 @@ Objects are also numbered backwards by type from the last one of
 You can say \fB2nd last box\fP to get the second-to-last box, or
 \fB3rd last ellipse\fP to get the third-to-last box.
 .PP
-In places where \fIn\fBth\fP is allowed, \fB`\fIexpr\fB'th\fP is also allowed.
+In places where \fIn\fBth\fR is allowed, \fB`\fIexpr\fB'th\fR is also allowed.
 Note that
 .B 'th
 is a single token: no space is allowed between the
@@ -947,7 +947,7 @@ abbreviated to \fB.t\fP, \fB.b\fP, \fB.l\fP and \fB.r\fP).
 .PP
 The names \fBcenter\fP, \fBtop\fP, \fBbottom\fP, \fBleft\fP and
 \fBright\fP can also be used (without the leading dot) in a prefix
-form marked by \fBof\fP; thus, \fPcenter of last circle\fB and
+form marked by \fBof\fP; thus, \fBcenter of last circle\fP and
 \fBtop of 2nd last ellipse\fP are both valid object references.
 .PP
 Arc objects also have compass point; they are the compass points of
@@ -1004,7 +1004,7 @@ numerator/denominator form or may be an ordinary number (values are
 \&\fInot\fP restricted to [0,1]).  As an alternative to this verbose
 syntax, you can say `\fIfraction\fP  \fB<\fP\fIposition1\fP \fB,\fP
 \fIposition2\fP\fB>\fP.'; thus, the example could also be written
-\fB1/3\fP <here, last ellipse>\fP.
+\fB1/3 <here, last ellipse>\fP.
 .KS
 .PS
 arrow up right;
@@ -1048,9 +1048,9 @@ objects.
 .KS
 .PS
 box invis wid 2 height 1;
-dot(last box .ne); "\fB(B,A)\fB is here" ljust at last circle + (0.1, 0.1);
+dot(last box .ne); "\fB(B,A)\fP is here" ljust at last circle + (0.1, 0.1);
 dot(last box .se); "B" ljust at last circle + (0.1, -0.1)
-dot(last box .sw); "\fB(A,B)\fB is here" rjust at last circle + (-0.1, -0.1);
+dot(last box .sw); "\fB(A,B)\fP is here" rjust at last circle + (-0.1, -0.1);
 dot(last box .nw); "A" ljust at last circle + (-0.1, 0.1)
 .PE
 .CE "5: Using (\fIx\fP, \fIy\fP) composition"
@@ -1368,16 +1368,17 @@ the usual way using parentheses.  GNU \fBgpic\fP allows logical
 operators to appear in expressions; ! (logical negation, not
 factorial), &&, ||, ==, !=, >=, <=, <, >.
 .PP
-Various built-in functions are supported: \fBsin(\fIx\fP)\fP,
-\fBcos(\fIx\fP)\fP, \fBlog(\fIx\fP)\fP, \fBexp(\fIx\fP)\fP,
-\fBsqrt(\fIx\fP)\fP, \fBmax(\fIx\fP,\fIy\fP)\fP,
-\fBatan2(\fIx\fP,\fIy\fP)\fP, \fBmin(\fIx\fP,\fIy\fP)\fP,
-\fBint(\fIx\fP\fB)\fP, and \fBrand()\fP, Both \fBexp\fP and \fBlog\fP are
+Various built-in functions are supported: \fBsin(\fIx\fB)\fR,
+\fBcos(\fIx\fB)\fR, \fBlog(\fIx\fB)\fR, \fBexp(\fIx\fB)\fR,
+\fBsqrt(\fIx\fB)\fR, \fBmax(\fIx\fB,\fIy\fB)\fR,
+\fBatan2(\fIx\fB,\fIy\fB)\fR, \fBmin(\fIx\fB,\fIy\fB)\fR,
+\fBint(\fIx\fB)\fR, and \fBrand()\fP.
+Both \fBexp\fP and \fBlog\fP are
 base 10; \fBint\fP does integer truncation; and \fBrand()\fP returns a
 random number in [0-1).
 .PP
 GNU \fBgpic\fP also documents a one-argument form or rand,
-\fBrand(\fIx\fP\fB)\fP, which returns a random number between 1 and
+\fBrand(\fIx\fB)\fR, which returns a random number between 1 and
 \fIx\fP, but this is deprecated and may be removed in a future
 version.
 .PP
@@ -1966,7 +1967,7 @@ multiple-part pattern:
 \&
 \&    line down from 1st box .s lineht;
 \&    A: line down;
-\&    line down from 2nd box .s; filter "\\fBhtml2ms";
+\&    line down from 2nd box .s; filter "\\fBhtml2ms\\fP";
 \&    B: line down;
 \&    line down from 3rd box .s; filter "\\fBformat\\fP";
 \&    C: line down;
@@ -2032,7 +2033,7 @@ Top: [
 
     line down from 1st box .s lineht;
     A: line down;
-    line down from 2nd box .s; filter "\fBhtml2ms";
+    line down from 2nd box .s; filter "\fBhtml2ms\fP";
     B: line down;
     line down from 3rd box .s; filter "\fBformat\fP";
     C: line down;
@@ -2238,8 +2239,6 @@ The \f(CWat\fP primitive sets the center of the current object.  The
 \f(CWwith\fP attribute fixes the specified feature of the given object
 to a specified location.
 .PP
-The \f(CWsolid\fR primitive is not yet supported in GNU \fBgpic\fR.
-.PP
 The \f(CWby\fR primitive is not documented in the tutorial portion of
 the Kernighan paper, and should probably be considered unreliable.
 .PP
@@ -2295,7 +2294,7 @@ Objects of a given type are numbered from 1 upwards in order of
 declaration; the \fBlast\fP modifier counts backwards.
 .PP
 The "'th" form (which allows you to select a previous object with an
-expression, as opposed to a numeric literal) is bnot documented in DWB
+expression, as opposed to a numeric literal) is not documented in DWB
 \fBpic\fR(1).
 .PP
 The following style variables control output: