title: How to implement created vs updated in an RSS feed
body: <p>I'd like to implement an RSS feed that has items that have distinguishable <em>created</em> and <em>updated</em> dates.</p>
  
  <p>I have a custom application that can display the difference, but I'd like "normal" RSS readers to fall back to the updated date.</p>
  
  <p>I could subvert <code>&lt;pubDate&gt;</code> and <code>&lt;dc:date&gt;</code> to be one and the other, but feedvalidator.org informs that the both shouldn't be used at the same time.</p>
  
  <p>Is there a namespace I could include that distinguishes between created and updated dates?  Or am I forced to create my own?</p>
  
  <p>What are the implications of creating your own namespace for custom fields?</p>