[Zope] Why base href?

[Christian Andreassen]

For some reason, Zope sometimes add a <base href=> tag in HTML documents.
When Zope is used in combination with Apache and Apache is configured to
rewrite incoming requests to a Zope folder that is not the root folder, this
will cause trouble if there are any relative URLs in the documents. The way
Zope determines the URL in the base href in combination with the way Apache
rewriting works will often, after clicking around the site a few times, lead
to something like www.mysite.org/mysiteroot/mysiteroot/mysiteroot/somedoc in
the address line of the browser. It looks ugly, it tricks the browser from
caching documents properly and visited links will look unvisited.

Does anybody know why <base href> is inserted automatically? Any tricks for
turning it off?