Zopers, In ZClasses it is possible to control where a ZClass instance should be permitted to be added, in other words show up in the factory listing in a ObjectManagers manage_main view. (I this correct by the way?) What I need to do is someway restrict in what Containers (myContainer subclass od ObjectManage ) my Zope Product Instances (myClass) should be abled to be added (show up in the factory list). When registerClass "myClass" in the initialize method of __init__.py it seems that the "myClass" gets addable everywhere. I have temporary solved this by removing the objects registration from the initialize method and adding manual add factories in the myContainer. This is bad though because the meta_types doesn't get registered and maybe some other problems as well. So how could I control dependencies for adding Zope Classes in other Zope Classes? Regards, Johan Carlsson