2.—(1) The licensee shall, for the purpose of distinguishing one storage tank from any other storage tank situated at the licensed premises, ensure that every such tank is clearly marked with—
(a)a number, a letter or a combination of both a number and a letter in such a manner that the number, letter or number and letter cannot be readily altered or obliterated; and
(b)(adjacent to that number, letter or number and letter) the maximum working capacity of the tank and the grade of petrol permitted to be stored therein under the petroleum-spirit licence granted in respect of the licensed premises.
(2) In this Schedule, any reference to the maximum working capacity of a storage tank shall be a reference to 97% of its actual capacity, expressed in litres.