I have been testing my project using the W3C Validation tool and it passes 100% with no errors and just 1 warning - XHTML 1.0 Transitional.
Warning - Conflict between Mime Type and Document Type
After some research I can find tons of definitions of the various MIME types, so the correct one for my project is 'application/xhtml+xml'.
But, where does it go - is it part of the DTD?
What other code do I need as this doesn't look complete on it's own?