No player shall grab the inside collar of the back or the side of the shoulder pads or jersey, or grab the jersey at the name plate or above, and pull the runner toward the ground. This does not apply to a runner who is in the tackle box or to a quarterback who is in the pocket.
Note: It is not necessary for a player to pull the runner completely to the ground in order for the act to be illegal. If his knees are buckled by the action, it is a foul, even if the runner is not pulled completely to the ground.
ARTICLE 16. HORSE-COLLAR TACKLE
No player shall grab the inside collar of the back or the side of the shoulder pads or jersey, or grab the jersey at the name plate or above, and pull the runner toward the ground. This does not apply to a runner who is in the tackle box or to a quarterback who is in the pocket.
Note: It is not necessary for a player to pull the runner completely to the ground in order for the act to be illegal. If his knees are buckled by the action, it is a foul, even if the runner is not pulled completely to the ground.