Paragraph 10
The unit of measurement to which the indication of price given under article 14 relates shall be the unit by reference to which quantities of motor fuel are delivered from pumps on the price display premises, and where that motor fuel is delivered—
by reference to the litre, the indication of price given under article 14 may include the equivalent price per gallon of the grade or type indicated under that article;
by reference to the gallon, the indication of price given under article 14 may include the equivalent price of the grade or type of motor fuel that is indicated pursuant to article 14 by reference to the litre:
Provided that where all or any of the pumps on the premises measuring in gallons are being adapted to measure in litres, during the period referred to in article 15(3) the price given under article 14—
shall be indicated by reference to the litre, and
may include the equivalent price per gallon.