a-z_\-\.]*)|())((\+[\-\._A-Za-z0-9]+)|())" /&gt;
    &lt;/xs:restriction&gt;
  &lt;/xs:simpleType&gt;

  &lt;!-- Dendian enumeration type --&gt;
  &lt;xs:simpleType name="DendianEnum"&gt;
    &lt;xs:restriction base="xs:token"&gt;
      &lt;xs:enumeration value="Little-endian" /&gt;
      &lt;xs:enumeration value="Big-endian" /&gt;
      &lt;xs:enumeration value="Configurable" /&gt;
      &lt;xs:enumeration value="*" /&gt;
    &lt;/xs:restriction&gt;
  &lt;/xs:simpleType&gt;

  &lt;!-- Dfpu enumeration type