<xs:element name="Parties" >
  <xs:annotation>
    <xs:documentation>Various parties involved in the business transaction to which this document pertains</xs:documentation>
  </xs:annotation>
  <xs:complexType>
    <xs:sequence>
      <xs:element minOccurs="0" ref="Seller"/>
      <xs:element ref="Buyer"/>
      <xs:element minOccurs="0" ref="Broker"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>