Article 1
A team may interfere with the opponents anywhere within bounds after obtaining possession by legally recovering (a) an opponent's fumble, (b) a dribbled ball, (c) a blocked kick, (d) a kick off, (e) a scrimmage kick, (f) a return kick, or by (g) intercepting an opponent's pass.
Interference is restricted to at or above the waist.
As soon as the ball has been touched by the opponents on a kick, or possession has changed on an intercepted pass, a blocked kick, or recovered fumble, the line of scrimmage and the neutral zone loses any significance, with respect to blocking above the waist restrictions.