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A passer who is standing still or fading backward after the ball has left his hand is obviously out of the play and must not be unnecessarily contacted by an opponent through the end of the down or until the passer becomes a blocker, or a runner, or, in the event of a change of possession during the down, until he assumes a distinctly defensive position. However, at any time after the change of possession, it is a foul if:
- an opponent forcibly hits the quarterback’s head or neck area with his helmet, facemask, forearm, or shoulder
- if an opponent lowers his head and makes forcible contact with any part of his helmet against any part of the passer’s body. This provision does not prohibit incidental contact by the mask or the helmet in the course of a conventional block.