7 CFR § 51.2338 - Standard pack.
(a) Fruit shall be fairly uniform in size and shall be packed in boxes, flats, lugs, or cartons and arranged according to approved and recognized methods. Containers shall be well filled; contents tightly packed but not be excessively or unnecessarily bruised by overfilling or oversizing. Fruit in the shown face of the container shall be reasonably representative in size and quality of the contents.
(b) When packed in closed containers the size shall be indicated by marking the container with the numerical count.
(c) Boxes, flats, lugs, or cartons:
(1) Fruit packed in containers with cell compartments, cardboard fillers or molded trays shall be of proper size for the cells, fillers, or molds in which they are packed, and conform to the marked count.
(2) In order to allow for variations incident to proper packing in other types of containers, for example, lugs, cartons, or boxes, the number of fruit shall not vary more than two from the marked count.
(d) “Fairly uniform in size” means that fruit in containers marked numerically to denote size may not vary in diameter more than 1/2 inch (12.7mm) in sizes 30 or larger; 3/8 inch (9.5mm) is sizes 31 through 38; and 1/4 inch (6.4mm) in sizes 39 or smaller. Not more than 5 percent, by count, of the fruit in any container may exceed the diameter range specified.
(e) “Diameter” means the greatest dimension measured at right angles to a line from stem to blossom end.
(f) In order to allow for variations incident to proper sizing and packing, not more than 10 percent, by count, of containers in any lot may fail to meet these requirements.