<xs:attribute name="PaymentTransactionTypeCode" use="optional">
    <xs:annotation>
        <xs:documentation xml:lang="en">This is used to indicate either a charge, reserve (deposit) or refund.</xs:documentation>
    </xs:annotation>
    <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
            <xs:enumeration value="charge">
                <xs:annotation>
                    <xs:documentation xml:lang="en">This indicates that an actual payment has been made.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="reserve">
                <xs:annotation>
                    <xs:documentation xml:lang="en">This indicates that a hold for the indicated amount has been placed on a credit card or that a cash amount has been taken from the customer to guarantee final payment.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="refund">
                <xs:annotation>
                    <xs:documentation xml:lang="en">This indicates that the payment amount of this PaymentDetail element is for a refund.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
        </xs:restriction>
    </xs:simpleType>
</xs:attribute>