On Wednesday 2006-12-06 09:05 +0900, olivier Thereaux wrote:
> Serving XHTML 1.0 content as text/html is perfectly legit per the  
> XHTML 1.0 specification, and the section 5.1 you quote. There is even  
> an section on how to ensure that content served that way can be  
> interpreted by legacy user-agents.

It's not just legacy user-agents.  It's *all* user-agents, per the
request of the HTML working group in
http://lists.w3.org/Archives/Public/www-html/2000Sep/0024 

I'm not sure if this ever made it in to any specifications, other
than the italicized wording added to Appendix C in the second
edition of XHTML 1.0:

# Note that this recommendation does not define how HTML conforming
# user agents should process HTML documents. Nor does it define the
# meaning of the Internet Media Type text/html. For these
# definitions, see [HTML4] and [RFC2854] respectively.
  -- http://www.w3.org/TR/2002/REC-xhtml1-20020801/#guidelines 

-David

-- 
L. David Baron                                <URL: http://dbaron.org/  >
           Technical Lead, Layout & CSS, Mozilla Corporation