A beacon looks like a little black button.  You can set a wrist unit to show the direction and distance of a beacon, so that you can find it.

During our first mission on Dancer 61, a man passed Tony a note, begging for help.  We went back secretly to speak to him – and couldn’t find him.  Since then, Tony usually carries a spare beacon.

He used it on Wotzit 4.  While we were visiting the planet, Naian crept near us.  We couldn’t talk to him then, because the leaders were around, but Tony slipped him a beacon.  We returned secretly, and used the beacon to find Naian.  See Report 10.

During our tramp through the jungle on Sting 3, we thought Kavi-Gaki might try to slip away, so we stuck a beacon to his collar without him knowing.  If he escaped, the beacon would help us to find him again.  See Report 39.

When Tony and Ngidado went into the jungle in Memnon 1, they left a beacon in Ngidado’s ship, so that they could find their way back to it.  See Report 48.