<xs:complexType name="PaymentMechanismType">
    <xs:choice>
        <xs:element ref="adsml:CreditCard" />
        <xs:element name="Invoice">
            <xs:complexType>
                <xs:sequence>
                    <xs:element name="MarkWith" type="adsml:LongStringType" minOccurs="0" />
                    <xs:element ref="SendCopyTo" minOccurs="0" maxOccurs="unbounded" />
                    <xs:element ref="adsml:Instructions" minOccurs="0" />
                </xs:sequence>
                <xs:attribute name="sendToPayer" type="adsml:BooleanType" use="required" fixed="true" />
            </xs:complexType>
        </xs:element>
        <xs:element name="Cash">
            <xs:complexType>
                <xs:sequence>
                    <xs:element ref="Reference" />
                </xs:sequence>
            </xs:complexType>
        </xs:element>
        <xs:element name="Check">
            <xs:complexType>
                <xs:sequence>
                    <xs:element name="CheckNumber" type="adsml:ShortTokenType" />
                </xs:sequence>
            </xs:complexType>
        </xs:element>
        <xs:element name="LetterOfCredit">
            <xs:complexType>
                <xs:sequence>
                    <xs:element ref="Reference" />
                </xs:sequence>
            </xs:complexType>
        </xs:element>
        <xs:element name="AccountDebit">
            <xs:complexType>
                <xs:sequence>
                    <xs:element ref="Reference" />
                </xs:sequence>
            </xs:complexType>
        </xs:element>
        <xs:element ref="adsml:Contract" />
        <xs:element name="OtherMechanism">
            <xs:complexType>
                <xs:sequence>
                    <xs:element ref="adsml:Properties" />
                </xs:sequence>
            </xs:complexType>
        </xs:element>
    </xs:choice>
</xs:complexType>

• PaymentMechanismType
• adsml-bo:Mechanism