13. It shall not be an offence under the principal Regulations to sell or advertise for sale any alcoholic drink described as “low alcohol” (or bearing any other word or description which implies that the drink being described is low in alcohol) in contravention of the provisions of regulation 38 of the principal Regulations and Schedule 7 thereto (as herein amended) where such drink was prepacked and labelled before the coming into force of these Regulations.