It’s a PRO plan tool. In the menu, under Tools, open the Driver notebook and put coloured tags on other drivers —Dangerous, Dirty driver, Bad connection, Smurf account, Hot lapper, Target, Likes to battle, Very fast, Real-life driver, Clean driver, Teammate, Friend, YouTuber and Twitch— and add your own notes. When you race them again, their icons show in the Relative and the Standings, right after the name or outside the overlay, on the left or the right. They also show on your phone and in your OBS stream.
The app records the drivers of every session on its own, so you tag them after the race, picking them from the ones you’ve raced with. Everything stays saved on your PC only. On the FREE plan the icons don’t show, but your notebook is kept; the 7-day PRO trial includes it. Step by step in the Driver notebook manual.