The Navigation Command and Control Grid or NAV GRID was designed to enable easy navigation and CAP control from a common fixed reference point. As an extended function of GND STAB, it enables TID readout of bearing and range from that set reference point, referred to as YY. Additionally, it also displays a grid extending from YY along a set threat axis. The purpose of the grid itself is to allow for quick position reference while a precise readout is available for a hooked target, as well as voice codes. Practically this is useful for Bullseye calls when receiving picture updates from controllers.