<xs:attribute name="Type" use="required">
    <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
            <xs:enumeration value="Base">
                <xs:annotation>
                    <xs:documentation xml:lang="en">The total of base ticket fees.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="Tax">
                <xs:annotation>
                    <xs:documentation xml:lang="en">The total of all taxes for the ticket fees.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="Total">
                <xs:annotation>
                    <xs:documentation xml:lang="en">The total of all ticket fees.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
        </xs:restriction>
    </xs:simpleType>
</xs:attribute>