Rule 7 – Section 1 – Article 4 – Offensive Team Requirements — At the Snap
Violation of each of the following (a-c) is a live-ball foul; the play is allowed to continue.
At the snap, Team A must be in a formation that meets these requirements:
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The conditions in 5(a)-5(c) are no longer in effect if prior to the snap a period ends or there is a timeout charged to the referee or one of the teams.