            use="optional" /&gt;
          &lt;xs:attribute name="Cclass"      type="xs:string"            use="required" /&gt;
          &lt;xs:attribute name="Cgroup"      type="xs:string"            use="required" /&gt;
          &lt;xs:attribute name="Csub"        type="xs:string"            use="optional" /&gt;
          &lt;xs:attribute name="Cvariant"    type="xs:string"            use="optional" /&gt;
          &lt;xs:attribute name="Cversion"    type="ComponentVersionType" use="optional" /&gt;
    