title: Select nodes that don't have a key with XSLT/XPath
body: <p>I'm using the Muenchian method to group nodes in an XML document.</p>
  
  <p>As part of my output, I'd like to select all of the nodes to which I have <em>not</em> assigned a key.</p>
  
  <p>I've tried</p>
  
  <pre><code>&lt;xsl:apply-templates select="*[key('kcWWPN','')]"/&gt;
  </code></pre>
  
  <p>but that doesn't appear to be working correctly, in that it is selecting no nodes.</p>
  
  <p>Any suggestions on the right way to do this?</p>