<xs:element name="TravelerRefNumber" minOccurs="0" maxOccurs="unbounded">
    <xs:annotation>
        <xs:documentation xml:lang="en">One or more travelers to whom this request applies</xs:documentation>
    </xs:annotation>
    <xs:complexType>
        <xs:attributeGroup ref="TravelerRefNumberGroup" />
        <xs:attribute name="RangePosition" use="optional">
            <xs:annotation>
                <xs:documentation xml:lang="en">Specifies whether this is the first or last traveler reference number in a range.</xs:documentation>
            </xs:annotation>
            <xs:simpleType>
                <xs:restriction base="xs:NMTOKEN">
                    <xs:enumeration value="First">
                        <xs:annotation>
                            <xs:documentation xml:lang="en">The first number in a range.</xs:documentation>
                        </xs:annotation>
                    </xs:enumeration>
                    <xs:enumeration value="Last">
                        <xs:annotation>
                            <xs:documentation xml:lang="en">The last number in a range.</xs:documentation>
                        </xs:annotation>
                    </xs:enumeration>
                </xs:restriction>
            </xs:simpleType>
        </xs:attribute>
    </xs:complexType>
</xs:element>