nsion base="xs:string"&gt;
        &lt;xs:attribute name="vendor"    type="xs:string"  use="required" /&gt;
        &lt;xs:attribute name="name"      type="xs:string"  use="required" /&gt;
        &lt;xs:attribute name="url"       type="xs:anyURI"  use="optional" /&gt;
        &lt;xs:attribute name="revision"  type="xs:string"  use="optional" /&gt;
      &lt;/xs:extension&gt;
    &lt;/xs:simpleContent&gt;
  &lt;/xs:complexType&gt;

  &lt;!-- package description root point --&gt;
  &lt;xs:element name="cprj"