<xs:attribute name="RoutingType" use="optional">
    <xs:annotation>
        <xs:documentation xml:lang="en">Specifies the travel routing preference.</xs:documentation>
    </xs:annotation>
    <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
            <xs:enumeration value="Normal">
                <xs:annotation>
                    <xs:documentation xml:lang="en">No special conditions.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="Mirror">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Outbound and inbound route of travel must be the same.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
        </xs:restriction>
    </xs:simpleType>
</xs:attribute>