Bad value X-UA-Compatible for attribute http-equiv on element meta

Question

I have used the same meta that HTML5 Boilerplate is using, and the W3C HTML validator complains:

Bad value X-UA-Compatible for attribute

Answer 1

.. may this be a good answer?

Set HTTP Header with PHP:

• http://www.joshuawinn.com/fix-html5-validator-error-bad-value-x-ua-compatible-for-attribute-http-equiv-on-element-meta/

This is not my own work but I hope it is useful to others too.