The Profile defines the "wire signature" of an operation in a wsdl:binding to be the fully qualified name of the child element ...

The Profile defines the "wire signature" of an operation in a wsdl:binding to be the fully qualified name of the child element of the soap:Body of the SOAP input message it describes. For the case of an empty soap:Body this name is an empty string. In the case of rpc-literal binding, the operation name is used as a wrapper for the part accessors. In the document-literal case, since a wrapper with the operation name is not present, the message signatures must be correctly designed so that they meet this requirement.