Remove datatype attribute from meta about tag I'm trying to validate my Drupal 7 website on http://validator.w3.org but I can't keep getting the following error:


  Attribute datatype not allowed on element meta at this point.


This is because &lt;meta about="/frontpage" property="sioc:num_replies" content="0" datatype="xsd:integer" /&gt; automatically gets the 'datatype=xsd:integer' attribute. I want to remove the datatype attribute altogether.
Apparently the meta tag isn't the problem. The problem is the validation service and how you use it. After some digging I found this article. The author suggest using a different validation type namely: http://validator.w3.org/nu/ with the following preset set in the additional options: "HTML5 + SVG 1.1 + MathML 2.0 + RDFa 1.1 + Microdata". This will validate said meta tags without any errors.