Hi Folks, OK.. I didn't hear much from my last plea for advice... I thought perhaps such a concrete problem would product lots of sage advice... but there's good news: here's another chance! Really Really Basic: If I have a class like so: class Shopper( OFS.SimpleItem.Item, ZPatterns.DataSkins.DataSkin, Acquisition.Implicit, AccessControl.Role.RoleManager, ): """ A Shopper """ # Specify a name for the item type: meta_type='Shopper' and let's say I define some attributes in the class.... id = 'default' email = '' _passwd = '' Now... let's further say that I want a developer using this class to be able to add propertysheets to instances of this class after I'm finished... to make customized versions of these objects. Also.. perhaps I want to take advantage of the 'automatic' nature of property sheets to provide a usable interface so that users can edit various properties. I was successful in adding a propertysheet using the /specialist/anobject/propertysheets/manage_addPropertySheet?id=foo&ns= technique.. which I'm pretty sure I could also implement programattically. ;-). But when I try: /specialist/anobject/propertysheets/foo/manage I get an attribute error looking for 'a_'. I get the same error when I try: /specialist/anobject/propertysheets/foo/manage_addProperty?id=blah&value=hh&type=string Any idea what's up with that? But no matter... I can't add 'email' to *any* propertysheet, even those in the ZClass, since it's already used in the class. So do I leave it out of the class and "hope" that someone defines it in some propertysheet somewhere? Do I do lots of: if hassattr(self, 'email') and so on.. in case somehow it didn't get taken care of? I *know* I missing something deep. I'm sure I'll say something dumb enough here soon.. and someone will point out my basic misunderstanding. ;-) thanks! -steve