Article 8 There shall be no unnecessary roughness. This shall include, but will not be limited to:
(g) If a player uses any part of his helmet (including the top/crown and forehead/”hairline” parts) or facemask to butt, spear, or ram an opponent violently or unnecessarily.
Note: This does not apply to contact against a runner, unless the runner is still considered to be a defenseless player, as defined in Rule 12, Section 2, Article 9
Article 9 It is a foul if a player initiates unnecessary contact against a player who is in a defenseless posture.
(a) Players in a defenseless posture are:
(1) A player in the act of or just after throwing a pass;
(b) Prohibited contact against a player who is in a defenseless posture is:
(1) Forcibly hitting the defenseless player’s head or neck area with the helmet, facemask, forearm, or shoulder, regardless of whether the defensive player also uses his arms to tackle the defenseless player by encircling or grasping him; and
(2) Lowering the head and making forcible contact with the top/crown or forehead/”hairline” parts of the helmet against any part of the defenseless player’s body.
Note: The provisions of (2) do not prohibit incidental contact by the mask or helmet in the course of a conventional tackle on an opponent