xlink:actuate

<xs:attribute name="actuate" default="onLoad">
  <xs:simpleType>
    <xs:restriction base="xs:string">
      <xs:enumeration value="onLoad"/>
      <xs:enumeration value="onRequest"/>
      <xs:enumeration value="other"/>
      <xs:enumeration value="none"/>
    </xs:restriction>
  </xs:simpleType>
</xs:attribute>