International humanitarian law
Military medical personnel engage in humanitarian work and are "protected persons" under international humanitarian law in accordance with the First and Second Geneva Conventions and their Additional Protocols, which established legally binding rules guaranteeing neutrality and protection for wounded soldiers, field or ship's medical personnel, and specific humanitarian institutions in an armed conflict. International humanitarian law makes no distinction between medical personnel who are members of the armed forces (and who hold military ranks) and those who are civilian volunteers. All medical personnel are considered non-combatants under international humanitarian law because of their humanitarian duties, and they may not be attacked and not be taken as prisoners of war; hospitals and other medical facilities and transports identified as such, whether they are military or civilian, may not be attacked either. The red cross, the red crescent and the red crystal are the protective signs recognised under international humanitarian law, and are used by military medical personnel and facilities for this purpose. Attacking military medical personnel, patients in their care, or medical facilities or transports legitimately marked as such is a war crime. Likewise, misusing these protective signs to mask military operations is the war crime of perfidy. Military medical personnel may be armed, usually with service pistols, for the purpose of self defense or the defense of patients.