500.13—Measurement of commodities by area measure only, how expressed.
For commodities measured in terms of area measure only declaration of net quantity in terms of square yards, square feet, and square inches shall be expressed in the following manner:
(b)
If at least 1 square foot (929 cm 2) but less than 4 square feet (37.1 dm 2 ), in terms of square feet with any remainder in terms of square inches or common or decimal fractions of the square foot.
(c)
If 4 square feet (37.1 dm 2) or more, in terms of the largest appropriate whole unit (square yards, square yards and square feet, or square feet) with any remainder in terms of square inches or common or decimal fractions of the square foot or square yard.