diff --git a/contrib/hgk b/contrib/hgk
--- a/contrib/hgk
+++ b/contrib/hgk
@@ -4,6 +4,8 @@
 # This program is free software; it may be used, copied, modified
 # and distributed under the terms of the GNU General Public Licence,
 # either version 2, or (at your option) any later version.
+#
+# See hgk.py for extension usage and configuration.
 
 
 # Modified version of Tip 171: