The International Committee of the Red Cross (ICRC) maintains a customary international humanitarian law (IHL) database. It contains over 160 norms of customary international law that govern the actions of nearly 90 countries relating to armed conflicts and humanitarian issues such as the distinction between combatants and civilians and conflicts among states and non-state groups.
"Customary international humanitarian law is a set of rules that come from a general practice accepted as law," Els Debuf, the ICRC's head of project for customary international humanitarian law, said. "A State does not have to formally accept a customary rule in order to be bound by it. If the practice on which a rule is based is widespread, representative and virtually uniform then that rule is binding on all States."