For a web service connector that uses a style/use of Document/Literal:

The input signature contains an optional document reference to the IS document type created to represent the operation input message. At run time, if you do not specify any input for the document reference variable or any of its child variables, Integration Server sends an empty SOAP body in the SOAP message.

The output signature contains a document reference to the IS document type created to represent the operation output message. This document reference is conditional and is only returned by the web service connector if the web service operation executes successfully. If returned at run time, this document reference contains the response from a successful invocation of a web service operation. If a SOAP fault occurred during execution of the web service operation, this document reference is not populated.

For a web service connector that uses a style/use of RPC/Encoded or RPC/Literal:

The input signature contains variables that represent the top-level elements in the operation input message. All of these variables are optional. At run-time, if you do not specify any input for the variable (or variables) that represent the input message, Integration Server sends an empty SOAP body in the SOAP message.

The output signature contains variables that represent the top-level elements in the operation output message. All of these variables are conditional and are only returned by the web service connector if the web service operation executes successfully. If returned, these variables contain the response from a successful invocation of a web service operation.