5. Where the method of filling a storage tank is by means of a pipe (whether in a single length or segmented) leading from the tank to a filling point not situated on, or immediately adjacent to, the tank itself, the licensee shall ensure that the said pipe is clearly marked on, or immediately adjacent to, the filling point with—
(a)the same number, letter or combination of both a number and letter and in the like manner as that with which the tank is marked; and
(b)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.