Validating XHTML5 in PHP?

Question

Background

I have made the decision to serve my website as application/xhtml+xml to anyone who will accept it. I understand that ther

Answer 1

The new (Nu) HTML5 Validator has RELAX NG schema for various presets including XHTML5

See https://bitbucket.org/validator/syntax/src/ed90a83ab0fd/relaxng https://github.com/validator/validator/tree/master/syntax/relaxng

Is this what you're looking for or am I confused?