title: XML processing instructions and white space
body: <p>I'm currently working on a XML/HTML parser for <code>node.js</code> (if your interested: <a href="https://github.com/fb55/node-htmlparser" rel="nofollow">link</a>). Let me get right to the point: I need to know how I should handle leading whitespace inside processing instructions. Should these be equal?</p>
  
  <ol>
  <li><code>&lt;?asdf ?&gt;</code></li>
  <li><code>&lt; ?asdf ?&gt;</code></li>
  <li><code>&lt;? asdf ?&gt;</code></li>
  <li><code>&lt; ? asdf ?&gt;</code></li>
  </ol>
  
  <p>I guess that strict XML will just allow the first one (but what's the expected behavior then? I don't want to validate, I want to accept the most constructs I can), it's more a philosophical question.</p>
  
  <p>Thanks in advance!</p>