The signature of the CF object method is determined from its type library. The Integration Service creates the CF object, and then calls the method on it to create the EP object, passing this method whatever parameters are required. This requires that the signature of the method consist of a set of input parameters, whose types can be determined from the type library, followed by a single output parameter that is an IUnknown** or an IDispatch** or a VARIANT* pointing to an IUnknown* or IDispatch*.
The input parameters hold the values required to initialize the EP object and the output parameter receives the initialized object. The output parameter can have either the [out] or the [out, retval] attributes. That is, the initialized object can be returned either as an output parameter or as the return value of the method. The datatypes supported for the input parameters are: