--- Games-Sokoban/Sokoban.pm	2010/05/12 00:16:44	1.7
+++ Games-Sokoban/Sokoban.pm	2010/05/12 00:24:37	1.8
@@ -165,6 +165,12 @@
 
 =item $binary = $level->as_binpack
 
+Binpack is a very compact binary format (usually 17% of the size of an xsb
+file), that is still reasonably easy to encode/decode.
+
+It only tries to store simplified levels with full fidelity - other levels
+can be slightly changed outside the playable area.
+
 =cut
 
 sub as_binpack {