title: Recursion in an XML schema?
body: <p>I need to create an XML schema that validates a tree structure of an XML document. I don't know exactly the occurrences or depth level of the tree.</p>
  
  <p>XML example:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;node&gt;
    &lt;attribute/&gt;
    &lt;node&gt;
      &lt;attribute/&gt;
      &lt;node/&gt;      
    &lt;/node&gt;
  &lt;/node&gt; 
  </code></pre>
  
  <p>Which is the best way to validate it?  Recursion?</p>