[Zope] Zclass nonfolderish?

[Chris McDonough]

After reading Amos' ZClasses Tutorial, my understanding is that you are
required to subclass the "Object Manager" base class to create class
instances that are folderish.

However, even if I leave the base class blank when creating a ZClass,
instances of the class present themselves as folderish (e.g. if I visit
/myClass/manage, I am presented with a management interface that allows me
to add objects "into" myClass).

Is this proper?  How do I create a ZClass which is not folderish?