Light Discipline

the concealment from the observation of the enemy in the air and on the ground of revealing luminous signs of troops, military facilities, industrial regions, and populated areas and the simulation of such signs at dummy facilities.

In light discipline, buildings and other facilities are lit internally through the use of camouflaged lighting, and entrances, windows, and other apertures are darkened by means of blinds and other devices. The external lighting of buildings is concealed through the use of low-powered lamps, which are turned off during an enemy air raid. Signal devices and transport lights are camouflaged with caps, visors, and screens.