I have an XHTML 5 page served with application/xhtml+xml which I want to get to validate, but the validator gives me trouble in its validation results:
Line
http://www.w3.org/TR/html-markup/meta.html says:
Changes in HTML5
Although previous versions of HTML allowed the http-equiv attribute on the meta element to have any number of possible values, the http-equiv attribute is now restricted to only the specific values described in this reference. Also, the new charset attribute is now allowed.
So, yes, it is not allowed anymore.