<xs:simpleType name="stateType">
  <xs:annotation>
    <xs:documentation>The state of an element (can be existing, deleted or undefined)</xs:documentation>
  </xs:annotation>
  <xs:restriction base="xs:NMTOKEN">
    <xs:enumeration value="existing"/>
    <xs:enumeration value="deleted"/>
    <xs:enumeration value="undefined"/>
  </xs:restriction>
</xs:simpleType>