--- a/onsub.py	Tue Mar 06 14:32:08 2012 +0100
+++ b/onsub.py	Tue Mar 06 14:36:55 2012 +0100
@@ -18,6 +18,13 @@
     each subrepository. By default, execution stops if CMD returns a
     non-zero exit code. Use --ignore-errors to override this.
 
+    If a POST-CMD is specified, this will be executed after all
+    subrepositories below the current subrepository has been visited.
+    This corresponds to a post-order traversal of the tree.
+
+    It is an error to specify a POST-CMD together with the
+    --breadth-first flag.
+
     Use --verbose/-v to print the command being run and the subrepo
     name for each run of CMD in a subrepo. Alternately, use
     --print0/-0 to print just the subrepo name followed by a NUL
@@ -175,5 +182,5 @@
            _('continue execution despite errors')),
           ('0', 'print0', None,
            _('end subrepository names with NUL, for use with xargs'))],
-         _('[-b] [-0] [--ignore-errors] CMD'))
+         _('[-b] [-0] [--ignore-errors] CMD [POST-CMD]'))
 }