ifc:IfcChangeActionEnum

<xs:simpleType name="IfcChangeActionEnum">
  <xs:restriction base="xs:string">
    <xs:enumeration value="nochange"/>
    <xs:enumeration value="modified"/>
    <xs:enumeration value="added"/>
    <xs:enumeration value="deleted"/>
    <xs:enumeration value="notdefined"/>
  </xs:restriction>
</xs:simpleType>