2.2 Common Message Syntax
This section specifies the syntax of SOAP messages, which are part of the Windows Server Update Services: Client-Server Protocol. The following rules apply to all SOAP messages in the protocol.
The soap:body element of the WSDL MUST specify use="literal", as specified in [WSDL] section 3.5.
For specific WSDL elements, the protocol specifies additional restrictions beyond those specified by the WSDL syntax of the elements<6>. For instance, in some cases, the protocol always requires the presence of an element in a message, even though its WSDL specification has a minOccurs attribute set to 0. In other cases, the protocol requires stronger typing on elements than is specified by the WSDL for the elements.
In all such cases, the additional restrictions are specified immediately after the WSDL is given.