title: Validation (HTML5): Attribute 'X' is not a valid attribute of element 'Y'
body: <p>I quite often do this:</p>
  
  <pre><code>&lt;input type="text" id="whatever" quantity="2" price="15" /&gt;
  </code></pre>
  
  <p>which causes VS2010 to issue the above warning -- I can live with the warnings because the inherent value in being able to hang data on form fields (which allows me later to pick them up for use in code e.g. <code>$('#whatever').attr('price')</code>, or simply <code>document.getElementById('whatever').price</code>) makes the nuisance warnings worth bearing.  However, I was wondering what the canonical approach to this problem is...</p>
  
  <p>anyone?</p>
  
  <p>TIA - ekkis</p>