<xs:simpleType name="SpecificationType" xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:restriction base="xs:string"> <xs:enumeration value="None" /> <xs:enumeration value="ByUser" /> <xs:enumeration value="ByPosTerminal" /> <xs:enumeration value="ByUserAndPosTerminal" /> </xs:restriction> </xs:simpleType>