[crda] setregdomain.1: various clarifications and improvements

[John W. Linville]

commit de35537396f310b7aa7d1ada4d49e31592b35a99
Author: John W. Linville <linville at tuxdriver.com>
Date:   Tue Nov 18 17:11:46 2014 -0500

    setregdomain.1: various clarifications and improvements
    
    Signed-off-by: John W. Linville <linville at tuxdriver.com>

 setregdomain.1 |   28 ++++++++++++++++++++++++++--
 1 files changed, 26 insertions(+), 2 deletions(-)
---
diff --git a/setregdomain.1 b/setregdomain.1
index 166eb1a..e246275 100644
--- a/setregdomain.1
+++ b/setregdomain.1
@@ -1,12 +1,36 @@
 .\" Copyright 2009 Red Hat, Inc.
-.TH segregdomain 1 2009-10-16 "CRDA" "User Commands"
+.TH segregdomain 1 2014-11-19 "CRDA" "User Commands"
 .SH NAME
-setregdomain \- set regulatory domain based on timezone
+setregdomain \- set regulatory domain based on country code
 .SH SYNOPSIS               
 .B setregdomain                  
 .SH DESCRIPTION
 setregdomain sets the regulatory domain for your system; it takes no
 arguments and is normally called via system script (eg, udev) rather
 than manually by an administrator.
+
+The regulatory domain is represented by an ISO / IEC 3166-1 alpha2
+country code.  By default, setregdomain attempts to determine
+the appropriate country code by examining the target of the
+.IR /etc/localtime
+symbolic link.  That information is used to look-up the matching
+country code in the
+.IR /usr/share/zoneinfo/zone.tab
+file.
+
+The country code look-up may fail.  This could be due to faulty
+or incomplete information in the
+.IR /usr/share/zoneinfo/zone.tab
+file, or the use of an actual file rather than a symlink for
+.IR /etc/localtime
+, among other possibilities.  In those cases the system
+administrator should define a COUNTRY environment variable in the
+.IR /etc/sysconfig/regdomain
+file.  This value will be used as the country code and the country
+code look-up will be skipped.
+.SH "FILES"
+.BR /etc/sysconfig/regdomain
+.BR /etc/localtime
+.BR /usr/share/zoneinfo/zone.tab
 .SH "SEE ALSO"
 .BR iw (1)