title: HTML5 on Eclipse PDT
body: <p>I'm new to Eclipse, using PDT (helios). I keep getting warnings for "Unknown Tag (article)", also besides 'article' theres unknown tag warnings with 'nav', 'footer', 'header', etc. What I can infer from this is that Eclipse has a problem with HTML5 Validation. </p>
  
  <p>I have one file Template.php which is used throughout the project and I've defined the DOCTYPE like so:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  </code></pre>
  
  <p>I tried looking into Project>Properties>Validation But I don't see anything there that I can change / modify for this. How would I ensure HTML5 is properly validated by eclipse?</p>