[Zope-dev] Possible to share zclass properties by subclassing?

I have several ZClasses I'm creating, and they share a number of common properties. Oh, I said, why don't I make an abstract ZClass for the common properties, and subclass my other ZClasses from that? But, oh well, the superclass view doesn't show up in the subclass manage screen, and I don't see the superclass property sheet as an option to select in the subclass "Views" tab. Am I off base here? Is there a way to share common properties? How should I do this? Thanks! Andrew