in territory controlled by an adverse party, they must be given an opportunity to surrender before being attacked unless it is apparent that they are engaging in a hostile act or attempting to escape. Airborne troops, or agents who are parachuting from an aircraft, whether in distress or not, are not given the protection afforded by this Article and, therefore, may be attacked during their descent. Article 43 deals with the identification of Armed Forces that are Party to a conflict, and states that combatants "shall be subject to an internal disciplinary system which, inter alia, shall enforce compliance with the rules of international law applicable in armed conflict." Article 47(1) "A mercenary shall not have the right to be a combatant or a prisoner of war." Articles 51 and 54 outlaw indiscriminate attacks on civilian populations, and destruction of food, water, and other materials needed for survival. Indiscriminate attacks include directly attacking civilian (non-military) targets, but also using technology such as biological weapons, nuclear weapons, and land mines, whose scope of destruction cannot be limited. A total war that does not distinguish between civilian and military targets is considered a war crime. Articles 56 and 53 outlaw attacks on dams, dikes, nuclear electrical-generating stations, and places of worship. The first three are "works and installations containing dangerous forces" and may be attacked only in ways that do not threaten to release the dangerous forces (i.e., it is permissible to capture them but not to destroy them). Articles 76 and 77, 15 and 79 provide special protections for women, children, and civilian medical personnel, and provide measures of protection for journalists. Article 77 forbids conscription of children under age 15 into the armed forces. It does allow, however, for persons under the age of 15 to participate voluntarily. Articles 43 and 44 clarify the military status of members of guerrilla forces. Combatant and prisoner of war status are granted to members of dissident forces when under the command of a central authority. Such combatants cannot conceal their allegiance; they must be recognizable as combatants while preparing for or during an attack. Article 35 bans weapons that "cause superfluous injury or unnecessary suffering", as well as means of warfare that "cause widespread, long-term, and severe damage to the natural environment". Article 85 states that it is a war crime to use one of the protective emblems recognized by the Geneva Conventions