Actually, we just call it Madison. We call other campuses by their city name. (Eau Claire, Milwaukee, Stout, Whitewater...etc) Nobody I've known calls it UW unless they're describing the campus they go to (ie UWEC, UWM, UWSP)...or they go to Madison, and think they're special because they consume more beer than the rest of us. Normally, the follow up to "I go (went) to UW" is "which one?".