The W3C Working Group Note XHTML Media Types - Second Edition contains updated guidelines for the use of different media types with XHTML documents – text/html vs. application/xhtml+xml. The note is about a year old now, so this will be old news to some readers. Better late than never, I suppose.
The document is now more focused on the text/html vs. application/xhtml+xml media types and includes Compatibility Guidelines for ensuring that documents can work with either media type.
One of the notable differences from the previous version of this note is that XHTML 1.1 documents may now be served as text/html provided that they conform to the compatibility guidelines.
