Code of Federal Regulations Title 7. Agriculture § 7.51.2966 Serious damage

(a) Discoloration (or stain) which covers, in the aggregate, one-third or more of the surface of the shell of an individual nut and which is brown, reddish brown, gray, or other color in pronounced contrast with the color of the rest of the shell or the majority of shells in the lot, or darker discoloration covering a smaller area if the appearance is equally objectionable;

(b) Perforated shells when the area affected aggregates more than that of a circle three-eighths of an inch in diameter. The term “perforated shells” means imperfectly developed areas on the shell resembling abrasions and usually including small holes penetrating the shell wall;

(c) Adhering hulls when affecting more than one-eighth of the shell surface in the aggregate;

(d) Shriveling when both halves of the kernel are affected by severe shriveling over an area totaling more than one-eighth of the surface;  or when both halves are affected over a greater area by lesser degrees of shriveling producing an equally objectionable appearance. When one of the halves of the kernel shows no shriveling, the kernel shall not be considered seriously damaged unless the other half shows shriveling to the extent that over 50 percent of its surface is severely shriveled, or a greater area is affected by lesser degrees of shriveling producing an equally objectionable appearance. Kernels which are thin in cross section, but which are otherwise normally developed shall not be considered as damaged;

(e) Rancidity or decay;  and,

(f) Uncured kernels which are wet, rubbery and “green”.