Organised armed groups are defined in relation to their activities being 'continuous combat function'.
The International Committee of the Red Cross released their Interpretive Guidance on Direct Participation in Hostilities, written by Nils Melzer. Although these ICRC guidelines are not legally binding, they are of considerable assistance to national governments struggling to develop policy to cope with the growth of non-combat participants in armed conflict including military contractors and irregular forces. These guidelines define organised armed groups in relation to their activities described as ‘continuous combat function’. The continuous combat function can be ‘openly expressed through the carrying of uniforms, distinctive signs or certain weapons’. The Interpretive Guidance indicates “the decisive criterion for individual membership in an organised armed group is whether a person assumes a continuous function for the group involving his or her direct participation in hostilities.”
DISCUSSION PAPER 2: DRONE ATTACKS, INTERNATIONAL LAW, AND THE RECORDING OF CIVILIAN CASUALTIES OF ARMED CONFLICT, p. 14