defensive player may not tackle or hold an opponent other than a runner. Otherwise, he may use his hands, arms, or body only:
(a) To defend or protect himself against an obstructing opponent.
Exception: An eligible receiver is considered to be an obstructing opponent ONLY to a point five yards beyond the line of scrimmage unless the player who receives the snap clearly demonstrates no further intention to pass the ball. Within this five-yard zone, a defensive player may chuck an eligible player in front of him. A defensive player is allowed to maintain continuous and unbroken contact within the five-yard zone until a point when the receiver is even with the defender. The defensive player cannot use his hands or arms to push from behind, hang onto, or encircle an eligible receiver in a manner that restricts movement as the play develops. Beyond this five-yard limitation, a defender may use his hands or arms ONLY to defend or protect himself against impending contact caused by a receiver. In such reaction, the defender may not contact a receiver who attempts to take a path to evade him.
(b) To push or pull opponent out of the way on line of scrimmage.
(c) In actual attempt to get at or tackle runner.
(d) To push or pull opponent out of the way in a legal attempt to recover a loose ball.
(e) During a legal block on an opponent who is not an eligible pass receiver.
(f) When legally blocking an eligible pass receiver above the waist.