1 files changed, 13 insertions, 1 deletions
diff --git a/lib/libc/locale/isupper.3 b/lib/libc/locale/isupper.3
index ec43a7a..3fb903e 100644
--- a/lib/libc/locale/isupper.3
+++ b/lib/libc/locale/isupper.3
@@ -36,7 +36,7 @@
 .\"     @(#)isupper.3	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd June 4, 1993
+.Dd October 6, 2002
 .Dt ISUPPER 3
 .Os
 .Sh NAME
@@ -77,8 +77,20 @@ The
 .Fn isupper
 function returns zero if the character tests false and
 returns non-zero if the character tests true.
+.Sh COMPATIBILITY
+Although
+.Fn isupper
+accepts arguments outside of the range of the
+.Vt "unsigned char"
+type in locales with large character sets,
+this is a
+.Bx 4.4
+extension and the
+.Fn iswupper
+function should be used instead for maximum portability.
 .Sh SEE ALSO
 .Xr ctype 3 ,
+.Xr iswupper 3 ,
 .Xr multibyte 3 ,
 .Xr toupper 3 ,
 .Xr ascii 7