[XHTML 1.0 Second Edition] Appendix C is informative, but section 5.1 requires conformance to it

Section 5.1 of the XHTML 1.0 Second Edition spec states:

        XHTML Documents which follow the guidelines set forth in
        Appendix C, "HTML Compatibility Guidelines" may be labeled with
        the Internet Media Type "text/html" [RFC2854], as they are
        compatible with most HTML browsers.
        
This is the only part of the XHTML spec which defines what documents may
be served as text/html (and is normative). However the entire of
Appendix C is *informative* and phrased in non-RFC 2119 language so, as
far as I can tell, doesn't actually make any requirements that need to
be followed.

-- 
David Dorward                           <http://dorward.me.uk/>
"Anybody remotely interesting is mad, in some way or another."
                             -- The Greatest Show in the Galaxy