It was slow this afternoon, as I was playing solo behind a foursome. To kill time, and because my short game really needs the work, I decided to practice chipping on and around the green after I finished a hole. In the back of my mind, I knew there was some rule about practicing during the round.
This is covered by Rule #5.
Rule #5.2 says that you can practice on the course before or between rounds in match play. In stroke play, you cannot practice on the course before the round. That's an interesting difference. Obviously you can practice on the range, and on any practice green or chipping area.
Rule #5.5 says that you can practice on and near the green of the hole you just completed, but you can't practice from any bunker. Oops. Looks like I get a couple of bonus strokes for that violation. I played solo, so I can't post my round anyway. The penalty would apply to your next hole.