diff -r 4f5ab60e71cc -r f1b6e7c09a6f schemas/base.py
--- a/schemas/base.py	Fri Jul 22 15:58:05 2011 +0200
+++ b/schemas/base.py	Tue Jul 26 10:33:26 2011 +0200
@@ -324,8 +324,9 @@
         'CWSource', inlined=True, cardinality='1*', composite='object',
         __permissions__=RELATION_MANAGERS_PERMISSIONS)
     cw_schema = SubjectRelation(
-        ('CWEType', 'CWRType', 'CWAttribute', 'CWRelation'),
+        ('CWEType', 'CWRType', 'CWRelation'),
         inlined=True, cardinality='1*', composite='object',
+        constraints=[RQLConstraint('NOT O final TRUE')],
         __permissions__=RELATION_MANAGERS_PERMISSIONS)
     options = String(description=_('allowed options depends on the source type'))