In describing or marking lettuce, packed or repacked within this State and offered for sale on a graded basis the letters "U.S." may be prefixed to any of the grade terms, and when so prefixed the lettuce to which they relate shall be regarded as represented as graded according to New York official lettuce grades.
N.Y. Comp. Codes R. & Regs. Tit. 1 § 189.1