lements to define the order of
 sorting. The sort keys are specified in major-to-minor order.</p>

<p>The expression used for sorting can be any string expressions. The following are
particularly useful:</p>

<ul>
<li>element-name, e.g. TITLE: sorts on the value of a child element</li>
<li>attribute-name, e.g. @CODE: sorts on the value of an attribute</li>
<li>".": sorts  on the character content of the element</li>
<li>"qname(.)": sorts on the name of the element</li>
</ul>

<p>Example 1:</p>
