[Zope] Is HTTP_MANAGE EnvVar only in Plone? and -w mapping

I partially figured it out (trying to reduce Plone down to Zope), it seems HTTP_MANAGE plays a trick with the accessRule.py External Method to set the Plone default location, which I am trying to cleanly nuke. That said, if using -w to have Zope listen on multiple ports, does each port get "mapped" to a location/URL in Zope/ZODB? Thanks, Michael.