An excuse, exception, or proviso which is not stated in the enacting clause of a statute creating a crime, or which is stated only by reference to other provisions of the statute, need not be negated in the indictment, information, or complaint unless it is necessary for a complete definition of the crime. If a statute which creates a crime permits an act, which is declared to be criminal, to be performed without criminality under stated conditions, the conditions need not be negated.
R.I. Gen. Laws § 12-12-11