<xsd:element name="ProviderRelationshipCode" minOccurs="0"> <xsd:simpleType> <xsd:restriction base="xsd:string"> <xsd:enumeration value="Established Patient" /> <xsd:enumeration value="Not Established Patient" /> <xsd:enumeration value="Not Known" /> </xsd:restriction> </xsd:simpleType> </xsd:element>