Hi there, I'm writing a product (in Python, not with ZClasses) which consists of: form - a folderish object to which you can add.. fields - a number of SimpleItemish objects that can be added to a form What I have working: * I can make the form behave like a folder by deriving it from OFS.ObjectManager * I have a number of fields that can be added anywhere in the Zope tree What I want to reach is this situation: * I want the form to behave like an folder, but only fields should be addable. and * Fields should not be addable anywhere but in a form. What set of incantations would accomplish this? Any example source? Or Zope source code I should study? Anything? Any hint in the right direction would be appreciated. Regards, Martijn