diff --git a/plone/app/discussion/comment.py b/plone/app/discussion/comment.py
index 8322fcf..b897730 100644
--- a/plone/app/discussion/comment.py
+++ b/plone/app/discussion/comment.py
@@ -47,8 +47,11 @@ class Comment(Explicit, Traversable, RoleManager, Owned):
         
         for k, v in kw:
             setattr(self, k, v)
-    
-    # convenience functions
+
+    @property
+    def in_reply_to(self):
+        # TODO
+        return None
     
     @property
     def __name__(self):
diff --git a/plone/app/discussion/conversation.py b/plone/app/discussion/conversation.py
index 9bb1842..101049d 100644
--- a/plone/app/discussion/conversation.py
+++ b/plone/app/discussion/conversation.py
@@ -44,11 +44,8 @@ class Conversation(Persistent, Explicit):
         # id -> comment - find comment by id
         self._comments = IOBTree()  
         
-        # # id -> IISet (children) - find all children for a given comment. 0 signifies root.
+        # id -> IISet (children) - find all children for a given comment. 0 signifies root.
         self._children = IOBTree()
-        
-        # id -> id (parent) - find the parent for a given comment. 0 signifies root
-        self._parents  = IIBTree()
     
     def getId(self):
         """
@@ -124,4 +121,3 @@ class CommentReplies(ConversationReplies):
     def __init__(self, context):
         self.conversation = context.__parent__
         self.root = context.comment_id
-    
\ No newline at end of file
diff --git a/setup.py b/setup.py
index f030365..8e57269 100644
--- a/setup.py
+++ b/setup.py
@@ -25,7 +25,7 @@ setup(name='plone.app.discussion',
       zip_safe=False,
       install_requires=[
           'setuptools',
-          # -*- Extra requirements: -*-
+          'collective.autopermission',
       ],
       entry_points="""
       # -*- Entry points: -*-