title: What is the meaning of '.?select=*.xml;recurse=yes' in xslt string?
body: <p>I've seen Michael Kay kindly respond to XSL questions with a template something like shown below. </p>
  
  <p>I'm wondering where the syntax for the string being passed to <code>collection()</code> is documented? I tried searching the XSL spec for some sort of wildcard pattern with recursion but came up empty. </p>
  
  <pre><code>&lt;xsl:template name="main"&gt;
    &lt;xsl:for-each select="collection('.?select=*.xml;recurse=yes')"&gt;
      &lt;xsl:result-document href="out/{tokenize(document-uri(.), '/')[last()]"&gt;
        &lt;xsl:apply-templates select="."/&gt;
      &lt;/xsl:result-document&gt;
    &lt;/xsl:for-each&gt;
  &lt;/xsl:template&gt;
  </code></pre>