[Zope-dev] Permissions

Hello, I would like to setup the security on a Zope server such that a user can edit permissions on something they own, but not grant more permissions than what they have acquired from the parent. If a user owns a folder they could grant "Owner" any permissions they want inside of that folder (Assuming they have the "Change permission" permission). Is there a way to limit which permissions a user can change? I would like to be able to delegate permissions. Such that if a user creates a folder they can grant other roles permissions up to the permissions they have acquired from the parent folder. Is this possible? I don't want that user to be able to grant themselves additional permissions. Thanks, -Brian Brinegar