Separating into defined categories of species, sex, length, weight, either at sea or onshore, or grading to sort into defined categories of some aspect of quality such as size or freshness. If used, the terms sorting and grading should be qualified to indicate the type of sorting or grading, e.g. Species sorting or size grading, to avoid misinterpretation. Sorting is often used in the context of defining the outgrade to be discarded because, the weight, or the degree of spoilage, freezer-burn, parasitic infestation, colour, blemishes, damage, taint, belly-burst, or some other quality aspect is unacceptable.