It is not posible to copy ZClasses, when I try to copy a ZClass in the Management Interface I get the error: 'The Item 'blorf' does not support that operation' I digged into that and found that in the ZClass.py there exists a method def cb_isCopyable: pass I was so crude to replace the pass with a 'return 1', restarted Zope and could now copy ZClasses as I wanted it. ----------------------------- My first question now: 0. Why are ZClasses not copyable? 1. Do I shoot into my foot with my hack or is that OK? ----------------------------- And now my second question I am working on a ZClass-intensive project and sometimes I want to add/remove base classes of a ZClass without redefining the whole class manually. in ZClass I have found a nice-sounding method _setBasesHoldOnToYourButts() <grin>, and the source is commented with '#Eeeek', hmmmm What are the risks for a good shot into my foot using this function? thanks phil