A Ping is a gameplay feature of Tom Clancy's Rainbow Six Siege. It allows players to place a marker on a location, giving teammates contextual ques to the location of enemies, gadgets, etc.
Only one marker may be placed at a time and will last for eight seconds apiece. There is a five second cooldown time between the placement of markers. Markers can only be placed when controlling an Operator directly instead of a Drone or camera. Additionally, their placement is dependent on the player's center field-of-view.
On February 17th, 2020, during the Six Invitational 2020, it was announced that an improved Ping system would be implemented during Year 5. Unlike the current system, players will be able to mark specific gadgets in order to improve coordination between team members. Additionally, players will be able to ping while using Drones.