From:  http://www.martsoft.com/docs/hierarchy.txt
Date:  1999-05-05

<?xml version="1.0" standalone="yes"?>

<!--
  Catalog hierarchy file:
    this file only contains a hierarchy of categories, no products;
    the catalog engine caches it in memory
-->

<catalog>

  <category name="Computer Product">

    <param name="NumberOfProduct" value="23"/>

    <attr name="Part ID" value=""/>
    <attr name="Vendor" value=""/>
    <attr name="Description" value=""/>
    <attr name="Cost" valuetype="float" value="" unit="dollar"/>

    <category name="Computer Hardware">
      <link name="" valuetype="Alternative"
         value="OCP://www.martsoft.com/UPYP/Computer Related/Computer/HW/"/>
    </category>

    <category name="Computer Software">
      <attr name="title" value="Software xxx"/>
      <attr name="Platform" value=""/>
      <attr name="Version" value=""/>

      <link name="" valuetype="CrossSell" value="OCP://www.xyz.com/sw/"/>

      <product name="11000078">
        <link name="" valuetype="PartOf" value=/Computer Product/Computer Software/11000079"> 
        <attr name="Part ID" value="33444IET">
        <attr name="Vendor" value="Microsoft">
        <attr name="title" value="Microsoft Word"/>
        <attr name="Cost" valuetype="float" value="29.99" unit="dollar"/>
        <attr name="Platform" value="Microsoft Windows 98"/>
        <attr name="Version" value="7.0"/>
        <attr name="Description" value="Word Editor"/>
          <value>
            <val>Inline pictures</val>
            <val>HTML ready</val>
          </value>
        </attr>
      </product> 

      <product name="11000079">
        <link name="" valuetype="HasPart" value=/Computer Product/Computer Software/11000078">
        <attr name="Part ID" value="33444FFY">
        <attr name="Vendor" value="Microsoft">
        <attr name="title" value="Microsoft Office 98"/>
        <attr name="Cost" valuetype="float" value="399.99" unit="dollar"/>
        <attr name="Platform" value="Microsoft Windows 98"/>
        <attr name="Version" value="7.0"/>
        <attr name="Description" value="Office product suite"/>
      </product>

    </category>

  </category>

  <category name="Real Estate">
  </category>

</catalog>