7 CFR § 51.1521
U.S. No. 1
July 6, 2020
“U.S. No. 1” consists of plums or prunes of one variety which are well formed, clean, mature but not overripe or soft or shriveled; which are free from decay and sunscald, and free from damage caused by broken skins, heat injury, growth cracks, sunburn, split pits, hail marks, drought spots, gum spots, russeting, scars, other disease, insects or mechanical or other means.
(a) Italian type prunes shall be fairly well colored and, unless otherwise specified, shall be not less than 11⁄4 inches in diameter. (See §51.1525.)
(b) [Reserved]