xs:typeDerivationControl

<xs:simpleType name="typeDerivationControl">
  <xs:annotation>
    <xs:documentation>A utility type, not for public use</xs:documentation>
  </xs:annotation>
  <xs:restriction base="xs:derivationControl">
    <xs:enumeration value="extension"/>
    <xs:enumeration value="restriction"/>
    <xs:enumeration value="list"/>
    <xs:enumeration value="union"/>
  </xs:restriction>
</xs:simpleType>