         implement one form of navigation. This list cannot be empty.
        </p>
      </field>
    </object>
  </type>
  <type name="NavigationTarget">
    <p>
      A description of a target to which the user can navigate.
    </p>
    <object>
      <field name="kind">
        <ref>ElementKind</ref>
        <p>
          The kind of the element.
        </p>
      </field>
      <field name="fileIndex">
        <ref>int</ref>
        <p>
          The index of the file (in the enclosing navigation resp