Regulation 24
Liquid capacity measures made of earthenware shall have their maximum purported values defined either—
(a)
by the brim of the measure; or
(b)
by an indelible line marked on the inside of the measure, so that—
(i)
in the case of measures of a maximum purported value not exceeding 1 quart, the distance from the bottom of the line to the brim does not exceed three-eights of an inch;
(ii)
in the case of measures of other maximum purported values, the said distance does not exceed three-quarters of an inch.