The Agricultural Marketing Service of the USDA classifies all meat (except pork, which falls under special guidelines) according to 8 categories: prime, choice, select, standard, commercial, utility, cutter and canner, as follows:

These classifications are determined at the slaughterhouse by qualified inspectors, tested annually to ensure uniform application of criteria. This guide applies particularly to beef, though it is roughly accurate for lamb, pork, and goat, as well.