American Football IFAF Approved Ruling 10-2-2
XII. During the return of a scrimmage kick, B40 blocks A80 in the back above the waist at the B-25. Team B’s ball carrier is downed with the ball in his possession at Team B’s 40-yard line.
RULING: Team B foul, illegal block in the back. Penalty – 10 yards from the spot of the foul. Team B’s ball, first and 10, from its 15-yard line. [Cited by 2-3-4-a, 9-3-6]