Related Rule
France
Practice Relating to Rule 4. Definition of Armed Forces
France’s Disciplinary Regulations (1975), as amended in 1982, states:
Soldiers in combat must not consider members of the armed forces or volunteer militias, including organized resistance movements, as combatants unless they are under a responsible command, wear a distinctive sign, carry arms openly and respect the laws and customs of war. 
France, Règlement de Discipline Générale dans les Armées, Decree No. 75-675 of 28 July 1975, replacing Decree No. 66-749, completed by Decree of 11 October 1978, implemented by Instruction No. 52000/DEF/C/5 of 10 December 1979, and modified by Decree of 12 July 1982, Ministère de la Défense, Etat-Major de l’Armée de Terre, Bureau Emploi, Article 9 bis (1); see also Manuel de droit des conflits armés, Ministère de la Défense, Direction des Affaires Juridiques, Sous-Direction du droit international humanitaire et du droit européen, Bureau du droit des conflits armés, 2001, pp. 39 and 70–71.
France’s LOAC Teaching Note (2000) states: “Every member of a paramilitary force or a partisan recognizable by a fixed distinctive sign and carrying arms openly is considered as a combatant.” 
France, Fiche didactique relative au droit des conflits armés, Directive of the Ministry of Defence, 4 January 2000, annexed to the Directive No. 147 of the Ministry of Defence of 4 January 2000, p. 2.
The instructions given to the French armed forces for the conduct of Opération Mistral, simulating a military operation under the right of self-defence or a mandate of the UN Security Council, state: “Armed forces that are subject to the law of war consist of all organized units and their personnel, under a command which is responsible for the conduct of its subordinates.” 
France, Etat-major de la Force d’Action Rapide, Ordres pour l’Opération Mistral, 1995, Section 5.
Upon ratification of the 1977 Additional Protocol I, France informed the States party to the 1977 Additional Protocol I that its armed forces permanently include the Gendarmerie. 
France, Reservations and declarations made upon ratification of the 1977 Additional Protocol I, 11 April 2001, § 7.