mdr

…Finally, Mozilla does support the Content-Base: header, which existed in HTTP 1.0 but was dropped from HTTP 1.1 due to the lack of interoperable implementations. The IETF requires at least two interoperable implementations before a draft can become a standard. Interoperating only with yourself is just a standards-compliant form of masturbation…

from http://diveintomark.org/archives/2004/01/02/relative-uris