[Zope] hiding includes from webacces

Hello, Is there a way to deny direct access to Objects, but allow them to be included into other documents? I have tried to setup a role "include" and set my index_html to proxy to this rule, but it did not work. i am trying to forbid direct access to includes. E.g: http://foo/standard_html_header should not be allowed, because standard_html_header is not a full page, but it is included in every page. Thank you in advance Nils Decker