diff -r 24a2c6ee6cb0 -r 0a3ec097a76c doc/groups.dox
--- a/doc/groups.dox	Fri Nov 28 06:38:20 2008 +0000
+++ b/doc/groups.dox	Fri Nov 28 11:26:51 2008 +0100
@@ -482,9 +482,18 @@
 */
 
 /**
+@defgroup dimacs_group DIMACS format
+@ingroup io_group
+\brief Read and write files in DIMACS format
+
+Tools to read a digraph from or write it to a file in DIMACS format data.
+*/
+
+/**
 @defgroup nauty_group NAUTY Format
 @ingroup io_group
 \brief Read \e Nauty format
+
 Tool to read graphs from \e Nauty format data.
 */