under the geneva convention, the red cross, red crescent and red crystal emblems provide protection for military medical services and relief workers in armed conflicts and is to be placed on humanitarian and medical vehicles and buildings. the original emblem that has a red cross on a white background is the exact reverse of the flag of neutral switzerland. it was later supplemented by two others which are the red crescent, and the red crystal. the red crescent was adopted by the ottoman empire during the russo-turkish war and the red crystal by the governments in 2005, as an additional emblem devoid of any national, political or religious connotation.