<name>licenses</name>
          <version>3.0.0+</version>
          <description>
            <![CDATA[
            This element describes all the licenses for this project.
            Each license is described by a {@code license} element, which
            is then described by additional elements.
            Projects should only list the license(s) that applies to the project

            <multiplicity>*</multiplicity>
          </association>
        </field>
      </fields>
    </class>
    <class xml.tagName="extension">
      <name>CoreExtension</name>
      <description>Describes a build extension to utilise.</description>
      <version>1.0.0+</version>
      <fields>
        <field>
          <name>groupId</name>
          <description>The group ID of the extension's artifact.</description>

   |       variables for plugins in the POM.
   |
   |-->
  <profiles>
    <!-- profile
     | Specifies a set of introductions to the build process, to be activated using one or more of the
     | mechanisms described above. For inheritance purposes, and to activate profiles via <activatedProfiles/>
     | or the command line, profiles have to have an ID that is unique.
     |

        </field>
      </fields>
    </class>

    <class xdoc.anchorName="requirement">
      <name>Requirement</name>
      <version>1.0.0/1.1.0</version>
      <description>Describes a component requirement.</description>
      <!-- see o.a.m.plugin.descriptor.Requirement -->
      <fields>
        <field>
          <name>role</name>
          <required>true</required>

        <field>
          <name>name</name>
          <required>false</required>
          <version>1.0.0+</version>
          <type>String</type>
          <description>
            The optional name that describes the mirror.
          </description>
        </field>
        <field>
          <name>url</name>
          <required>true</required>
          <version>1.0.0+</version>
          <type>String</type>

      <fields>
        <field>
          <version>1.0.0</version>
          <name>expressions</name>
          <description>The list of plugin parameter expressions described by this
            document.</description>
          <association>
            <type>Expression</type>
            <multiplicity>*</multiplicity>
          </association>
        </field>
      </fields>