<xs:attribute name="ReturnType" use="optional">
    <xs:annotation>
        <xs:documentation xml:lang="en">Code indicating whether travel must commence or be completed in order to satisfy the stay restriction.</xs:documentation>
    </xs:annotation>
    <xs:simpleType>
        <xs:restriction base="xs:string">
            <xs:enumeration value="C">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Return travel must be Completed.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="S">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Return travel must be Started.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
        </xs:restriction>
    </xs:simpleType>
</xs:attribute>