-Every pair of different files with same content are listed, which
-results in K^2 printed lines when K files are similar.
+None known, probably many. Valgrind does not complain though.
+
+.SH "WISH LIST"
+
+The format of the output should definitely be improved. Not clear how.
+
+The comparison algorithm could definitely use some MD5 kind of
+signature. However, I doubt it would improve speed much.
+
+Their should be some fancy option to link two instances of the command
+running on different machines to reduce network disk accesses.
+
+.SH "EXAMPLES"
+
+.B finddup -cg blah something
+
+.fi
+List files found in \fB./blah/\fR which have a matching file with same
+content in \fB./something/\fR. Do not display the group IDs.
+
+.P
+.B finddup sources not:/mnt/backup
+
+.fi
+List all files found in \fB./sources/\fR which do not have
+content-matching equivalent in \fB/mnt/backup\fR.
+
+.P
+.B finddup tralala cuicui
+
+.fi
+List groups of files with same content which exist both in
+\fB./tralala/\fR and \fB./cuicui/\fR.