<xs:complexType name="ItemIdBase"> <xs:sequence> <xs:element name="Id" type="SimpleId" minOccurs="0"> <xs:annotation> <xs:documentation source="http://www.openapplications.org/oagis">Is the Identifier of the Item.</xs:documentation> </xs:annotation> </xs:element> <xs:element ref="EANUCC13" minOccurs="0" /> <xs:element ref="UPC" minOccurs="0" /> </xs:sequence> </xs:complexType>