git: 384789947054 - stable/13 - ifconfig.8: Document limitation of groupname

The branch stable/13 has been updated by meta:

URL: https://cgit.FreeBSD.org/src/commit/?id=38478994705468fcc878a6c40693cd9a3f29e086

commit 38478994705468fcc878a6c40693cd9a3f29e086
Author:     Koichiro Iwao <meta@FreeBSD.org>
AuthorDate: 2023-06-20 10:14:39 +0000
Commit:     Koichiro Iwao <meta@FreeBSD.org>
CommitDate: 2023-07-11 00:20:03 +0000

    ifconfig.8: Document limitation of groupname
    
    Approved by:            kp
    MFC after:              1 week
    Differential Revision:  https://reviews.freebsd.org/D40645
    
    (cherry picked from commit 9aca30d87804b9b9f646f9ef3ad5ae6af81fd40a)
---
 sbin/ifconfig/ifconfig.8 | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sbin/ifconfig/ifconfig.8 b/sbin/ifconfig/ifconfig.8
index 99a858aec021..e7d41da45bec 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 July 11, 2022
+.Dd June 20, 2023
 .Dt IFCONFIG 8
 .Os
 .Sh NAME
@@ -467,6 +467,9 @@ This action does not automatically disable routes using the interface.
 .It Cm group Ar groupname
 Assign the interface to a
 .Dq group .
+The
+.Ar groupname
+may not be longer than 15 characters and must not end in a digit.
 Any interface can be in multiple groups.
 .Pp
 Cloned interfaces are members of their interface family group by default.