Signalling lights

thumb|right|A burning torch, discarded on the road in the wake of the Lewes Bonfire Night celebrations

lights on a vessel, aircraft or spacecraft giving information on a craft's position, heading, and status

device used on a vehicle to signal emergencies

system of beacons stretching across Anatolia

Phryctoria () was a semaphore system used in Ancient Greece. The phryctoriae were towers built on selected mountaintops so that one tower (phryctoria) would be visible to the next tower (usually 20 miles away). The towers were used for the transmission of a specific prearranged message. One tower would light its flame, the next tower would see the fire, and light its own.

thumb|right|300px|Photograph showing Balisor beacons in use on high voltage cables Balisor is a system of illuminated beacons for high voltage power lines using a cold-cathode low-pressure neon lamp, used as an aircraft warning light.