South Dakota Administrative Rules
Title 12 - Department of Agriculture
Article 12:26 - Eggs and egg products
Chapter 12:26:01 - Definitions
Section 12:26:01:02 - Terms defining shell quality

(1) "Clean," a shell that is free from foreign material and from stains or discolorations that are readily visible. An egg may be considered clean if it has only very small specks or slight stains and if such specks or stains are not of sufficient number or intensity to detract from the generally clean appearance of the egg. Eggs that show traces of processing oil on the shell are considered clean unless otherwise soiled;

(2) "Dirty," an unbroken shell which has dirt or foreign material adhering to its surface, which has prominent stains, or which has moderate stains covering more than one-thirty-second of the shell surface if localized or one-sixteenth of the shell if scattered;

(3) "Practically normal," or "AA or A quality," a shell that approximates the usual shape and that is free from thin spots. Ridges and rough areas that do not materially affect the shape and strength of the shell are permitted;

(4) "Abnormal," or "B quality," a shell that may be somewhat unusual in shape or decidedly misshapen, that may be faulty in soundness or strength, or that may show pronounced ridges or thin spots.