diff -r 5bf56c758e02 -r be1d10595b7b src/Doc/Classes/Classes.thy
--- a/src/Doc/Classes/Classes.thy	Sun Sep 07 17:51:28 2014 +0200
+++ b/src/Doc/Classes/Classes.thy	Sun Sep 07 17:51:32 2014 +0200
@@ -627,7 +627,9 @@
       together with associated operations etc.
 
     \item[@{command "class_deps"}] visualizes the subclass relation
-      between all classes as a Hasse diagram.
+      between all classes as a Hasse diagram.  An optional first sort argument
+      constrains the set of classes to all subclasses of this sort,
+      an optional second sort argument to all superclasses of this sort.
 
   \end{description}
 *}