Adjust the VLAN section of the ifconfig(8) man page to better reflect

reality:

1. Only 12-bit VLAN Identifiers, not full 16-bit VLAN tags can be set using
   ifconfig vlan.

2. When we mean VLAN Identifiers, spell it that way, rather than as VLAN tag.

MFC after:	3 days
Sponsored by:	Adara Networks, Inc.

1 files changed, 5 insertions, 4 deletions

diff --git a/sbin/ifconfig/ifconfig.8 b/sbin/ifconfig/ifconfig.8
index 3c86c04..e9c6995 100644
--- a/sbin/ifconfig/ifconfig.8
+++ b/sbin/ifconfig/ifconfig.8
@@ -28,7 +28,7 @@
 .\"     From: @(#)ifconfig.8	8.3 (Berkeley) 1/5/94
 .\" $FreeBSD$
 .\"
-.Dd December 17, 2011
+.Dd January 4, 2012
 .Dt IFCONFIG 8
 .Os
 .Sh NAME
@@ -2378,7 +2378,7 @@ interfaces:
 .It Cm vlan Ar vlan_tag
 Set the VLAN tag value to
 .Ar vlan_tag .
-This value is a 16-bit number which is used to create an 802.1Q
+This value is a 12-bit VLAN Identifier (VID) which is used to create an 802.1Q
 VLAN header for packets sent from the
 .Xr vlan 4
 interface.
@@ -2400,7 +2400,7 @@ diverted to the specified physical interface
 .Ar iface
 with 802.1Q VLAN encapsulation.
 Packets with 802.1Q encapsulation received
-by the parent interface with the correct VLAN tag will be diverted to
+by the parent interface with the correct VLAN Identifier will be diverted to
 the associated
 .Xr vlan 4
 pseudo-interface.
@@ -2439,7 +2439,8 @@ pseudo device, disassociate the parent interface from it.
 This breaks the link between the
 .Xr vlan 4
 interface and its parent,
-clears its VLAN tag, flags and its link address and shuts the interface down.
+clears its VLAN Identifier, flags and its link address and shuts the interface
+down.
 The
 .Ar iface
 argument is useless and hence deprecated.