Custom (law)

In law, custom, or customary law consists of established patterns of behaviour that can be objectively verified within a particular social setting. The modern codification of civil law developed out of the customs, or coûtumes of the middle ages, expressions of law that developed in particular communities and slowly collected and written down by local jurists. Such customs having the force of law when they because the undisputed rule by which certain entitlements (rights) or obligations were regulated between members of a community. see also Consuetudinary law.

In international law customary law refers to the Law of Nations or the legal norms that have developed through the customary exchanges between nations be they based on diplomacy or upon agression and are distinguished from the treaty law that has developed on bilateral or multilateral basis betweeen nations and mostly regulated by the United Nations system since 1945.

See also Consuetudinary.