674. For the purposes of sections 20, 24 to 26 and 27.1 of the Act respecting the Ministère du Revenu (chapter M-31), an amount collected as tax in respect of a supply referred to in section 671 is deemed to have been collected under a fiscal law. Similarly, for the purposes of sections 21 and 21.1 of the said Act in respect of a person who has made a supply referred to in section 671, such an amount is deemed to have been collected under a fiscal law. This section has effect from 25 October 1991.