A Marker Beacon is a Tau vehicle system that consists of enhanced optical processors and long-range communicators. With a Marker Beacon, a vehicle can accurately guide the deployment of Battlesuit-equipped warriors dropping into battle from transports far overhead. Devilfish assigned to Pathfinder scout teams are sometimes fitted with Marker Beacon systems, whilst all Tetras have one as standard.
- Codex: Tau Empire (4th Edition), pg. 38