I just came back after a 1 month ban, so bear with me if I've tried searching the keyword 'R', "R", R functionality in the search bar and have found nothing.
When did they add this to Gaming.SE? When you press R a list of things come up I assume that show your achievements? Not sure what's going on and what the intent of the feature is.
This only shows up on Gaming.SE and not any other SE site.