I know there is an active bug report on the tree tag using the sort option when not all items in the current folder have a property and that propert is used as a sort key... My problem is a bit simpler -- I have a jested group of folders ( say A, B, and C) enclosed in a folder (say OUTER). The structure is OUTER A B C which I am trying to render <dtml-tree OUTER sort="displayOrder"> <dtml-var title_and_id> </dtml-tree> I have set a property 'displayOrder" for each of the folders A, B, and C using the ZMI. (In the real world it gets set programmatically, but ...) Assuming that the sorting were to occur, I want the order to be B, C, A and have set the displayOrder values appropriately as strings. Running the progam fragment in a wrapper generates the error: Attribute Error: displayOrder with a reference in TreeTag.py where displayOrder is used in a getattr() call. Are properties not attributes of an object? What's the problem?