ARTICLE 4.Violation of each of the following (a-c) is a live-ball foul; the play is allowed to continue.
a. Formation. At the snap Team A must be in a formation that meets these requirements:
1. All players must be inbounds.
2. All players must be either linemen or backs (Rule 2-27-4).
Approved Ruling 7-1-4 VIII. Team A lines up with A11 ten yards directly behind the snapper. The other three backs are split wide, all outside the tackle box. Only four Team A linemen have uniform numbers between 50 and 79. A11 receives the backward pass from the snapper with Team A in this formation. RULING: Live-ball foul. Illegal formation, not enough players numbered 50-79 on the line of scrimmage. Team A is not is a scrimmage kick formation, because in this alignment it is not obvious that a kick will be attempted. (Rule 2-16-10)
3. At least five linemen must wear jerseys numbered 50 through 79 (Exception:When the snap is from a scrimmage kick formation, par. 5 below.)
4. No more than four players may be backs.
5. In a scrimmage kick formation at the snap (Rule 2-16-10) Team A may have fewer than five linemen numbered 50-79, subject to the following conditions:
(a) Any and all linemen not numbered 50-79 who are ineligible receiver(s) by position become exceptions to the numbering rule when the snapper is established.
(b) Any and all such numbering-exception players must be on the line and may not be on the end of the line. Otherwise, Team A commits a foul for an illegal formation.
(c) Any and all such players are exceptions to the numbering rule throughout the down and remain ineligible receivers unless they become eligible under Rule 7-3-5 (forward pass touched by an official or a Team B player).
The conditions in 5(a)–5(c) are no longer in effect if prior to the snap a period ends or there is a timeout charged to the referee or one of the teams.
PENALTY [a-c]—Live-ball foul: Five yards from the previous spot [S19 or S20]. For live-ball fouls occurring when or after the snap starts during scrimmage kick plays other than field goal plays: Five yards from the previous spot or if the kick crosses the neutral zone, five yards from the spot where the subsequent dead ball belongs to Team B [S19 or S20].