If the system profile parameter auth/rfc_authority_check is set (value 1), then the System automatically checks at the CALL FUNCTION keyword whether the authorizations user has the required RFC authorization.
The RFC authorization object is S_RFC Authorization check at RFC access. The authorization checks access to function modules by function module group. That is, whether a user has the right to run function modules that belong to a particular group.
You can test a user’s RFC authorization with the function module AUTHORITY_CHECK_RFC. This function module returns RC = 0 if the user is authorized for the group that you name. The function module does not check whether an authority check will actually take place.