[Zope] Visibility and Copy&Paste support

I've understood that in product development I have to register all my classes with registerClass() that I want to, as instanciated objects, copy/cut & paste. Some of these objects I don't want to encourage people to create via the ZMI and I don't want to clutter up the "Add new object drop down" with stuff that can't be added. If I register the class, but set 'visibility=None' I still can't copy/cut & paste the instanciated objects. Why? What's the point of the 'visibility=None' parameter? -- Peter Bengtsson, work www.fry-it.com home www.peterbe.com hobby www.issuetrackerproduct.com