A paramilitary is a semi-militarized force whose organizational structure, tactics, training, subculture, and (often) function are similar to those of a professional military, but which is not included as part of a state's formal armed forces. Under the law of war, a state may incorporate a paramilitary organization or armed agency (such as a national police, a private volunteer militia) into its combatant armed forces. The other parties to a conflict have to be notified thereof.