specify either [in] or [out] attribute.

Either the [in] or [out] attribute must be specified by the parameter. When the parameter is passed from a client to the server, specify the [in] attribute. When the parameter is passed from the server to a client, specify the [out] attribute.

S: Continues syntactic and semantic analyses, without generating stubs.

O: Specify either the [in] or [out] attribute.