Custom

Custom, a law not written but established by long custom by consent of the people. Customs are either general or particular. General customs are the universal rule of the whole kingdom (e.g. primogeniture) and form the common law in its stricter and more usual signification. Particular customs are those which mostly affect particular districts, as gavelkind in Kent. The courts are bound to take notice of general customs, but particular customs must be both pleaded and proved before they are judicially allowed. Moreover, a general custom is always good, but a particular custom in order to be good must be reasonable, certain, compulsory, immemorial, and possible in law.