I'm in way over my head here, not having encompassed XML. Thus, apologies in advance for any clueless content here. What I think we might do is declare a number of entities that are bound to the time-varying string representations of Python objects, and free us from the rather clumsy-appearing var syntax (sorry!). My first question is whether we can declare an entity in-line using XML or if it must be declared in the DTD. What I really want to do is something like <!ENTITY big_font SYSTEM "./big_font"> where "foo" is a property of the folder object, and then be able to say: <font name="&big_font"> and have that bound to the run-time string representation of the property. If you do a subsequent <?zope expr "big_font="LucidaTypewriterSoAndSo"> a subsequent reference to the entity &big_font should return the new value. So, does that <!ENTITY> tag have to be in the DTD, or may I declare them on the fly? Thanks Bruce -- The $70 Billion US "budget surplus" hardly offsets our $5 Trillion national debt. The debt increased by $133 Billion in the same year we found a "surplus". More debt is predicted for 1999. See www.concordcoalition.org . Bruce Perens K6BP bruce@pixar.com 510-620-3502 NCI-1001