--- a/Behavior.st	Wed Nov 18 12:11:39 2015 +0100
+++ b/Behavior.st	Wed Nov 18 12:54:41 2015 +0100
@@ -3569,6 +3569,11 @@
 !
 
 isAbstract
+    "true if this is an abstract class 
+     (has no direct instances, should not be instantiated).
+     Usually, this means that it only provides shared protocol for its
+     subclasses, which should be used."
+    
     ^ false
 !
 
@@ -3632,6 +3637,14 @@
     "Created: / 06-08-2006 / 15:23:57 / cg"
 !
 
+isUtilityClass
+    "a utility class is one which is not to be instantiated,
+     but only provides a number of utility functions on the class side.
+     It is usually also abstract"
+     
+    ^ false
+!
+
 isVisualStartable
     ^ false