Add a little comment about the serial key format.

diff --git a/config.pm b/config.pm
index f9d0897d63aecfebc3af10d9c0f50efcc2f2d4f0..94f4ea1775d4bbfbb27d93be0df3f68b1d4d2f79 100644 (file)
--- a/config.pm
+++ b/config.pm
@@ -32,6 +32,9 @@ our @masters = (
        'Sesse',
 );
 
+# ChessOK serial key (of the form NNNNN-NNNNN-NNNNN-NNNNN-NNNNN-NNNNN)
+# for looking up 7-man tablebases; undef means no lookup. Note that
+# you probably need specific prior permission to use this.
 our $tb_serial_key = undef;
 
 eval {