My point about the negotiation algorithm

The point of the XHTML Media Types note  
(http://www.w3.org/MarkUp/2010/ED-xhtml-media-types-20100218/) is to  
explain how to deliver XHTML to a browser.

If the browser says it accepts application/xhtml+xml, our job is done: use  
that media type; you don't have to follow any extra guidelines.

However, if it is a legacy browser, and doesn't accept  
application/xhtml+xml, then there is a fallback: deliver it as text/html  
(but make sure it won't hiccup on your content by following a number of  
guidelines).

So even if a browser says it accepts both media types, even if it says it  
'prefers' text/html (via a q value), our aim is to deliver XHTML, and so  
should use the application/xhtml+xml media type.

Steven