I was always under the impression that on a “normal" 4 exit roundabout (i.e. two roads crossing), you would indicate left if going left, right if going right, and no indication if going straight on. Then whichever way you're going you indicate left when passing the exit before. However, a number of drivers indicate right when going straight on, which means I stop expecting them to continue around but could've entered the roundabout. Am I incorrect here? Was there a time when something different was taught?