Hi! I patched TreeTag.py so that <dtml-tree> accepts a new parameter "urlparam_expr". It works like urlparam, except that it will take a python expression and evaluate it before creating the querystring for the expanding and contracting widget links. It's a "hotfix product", so you don't have to change your Zope sources. You can get it here: http://www.zope.org/Members/Barabbas/TreeTagPatch I've put the feature request for <dtml-tree> in the Collector, too: http://classic.zope.org:8080/Collector/bugsAndFeatures It's only three little locations that I patched. Maybe someone that knows Zope better than I do can have a look and verify that the patch is ok. Seems to me, but you know... Thanks, Danny