[Zope] Authentication, Anonymous and Public

I'm running into a problem after implementing jcNTUserFolder in a subfolder of my site. Users can access the root level or particular subfolders anonymously. Once a user accesses the protected NTUserFolder, the credentials are saved in the browser. If the user then returns to the anonymous area, they can no longer access th folder due to the browser credentials. Does Zope have a mechanism equivalent to the Novell NDS Public access? that is to say: Anonymous = not authenticated. Everyone = authenticated users (that are members of the group) Public = authenticated and anonymous users. I'd like the default access to be "anybody and their brother" rather than "those people who haven't logged in"