Where the punt returner can catch the ball and guarantee he doesn't get hit when it is obvious that a player has him lined up. I think he should be able to signal this by raising his hand before the ball gets to him. I think we should call it a "fair catch" or something like that.
This rule needs to be in place so these boys don't get hurt. Then, if a coach tells a kick returner not to call a fair catch, he should be called out for endangering the health of his player and be ejected for a half.