American Football Rules IFAF Approved Ruling 3-1-3:XI-XIV

XI. After the end of the first possession series by Team A, Team B commits a dead-ball personal foul. RULING: Team B starts its possession series on the 40-yard line, first and 10. [Cited by 3-1-3-g]
XII. During the first possession series of a period, A12 throws a forward pass and Team A is flagged for an illegal shift. B25 intercepts the pass, and B38 (a) clips or (b) commits a flagrant
personal foul before B25 crosses Team A’s goal line. RULING: Score not allowed. The fouls cancel and the down is not repeated. Team A’s possession series is ended, and Team B begins its possession series at the 40-yard line. In(b), B38 is disqualified. [Cited by 3-1-3-g]
XIII. During the second possession series of a period, B25 intercepts a pass and carries the ball across Team A’s goal line. During the run, B79 clips at midfield. RULING: No touchdown. Either the game is over, or the next period will start with first and 10 at either the 12½ or40-yard lines as the penalty carries over. [Cited by 3-1-3-g]
XIV. During the first possession series B37 intercepts a forward pass and has a clear field to the goal line when he makes an obscene gesture toward the nearest opponent. RULING: Team
B’s score is cancelled and the penalty is carried over. Team B begins its possession series on the 40-yard line, first and 10. (Rules 3-1-3, 10-2-7-a and 10-2-7-b). [Cited by 3-1-3-g]