Rule 9 Scrimmage Kicks
ARTICLE 3. DEFENSIVE TEAM FORMATION
Item 2: Field Goal or Try Kick Formation. When Team A presents a field goal or Try Kick formation:
- A Team B player, who is within one yard of the line of scrimmage, must have his entire body outside the snapper’s shoulder pads at the snap.
- No more than six Team B players may be on the line of scrimmage on either side of the snapper at the snap.
Penalty: For illegal formation by the defense: Loss of five yards.
- Team B players cannot push teammates into the offensive formation.
Penalty: For pushing teammates into offensive formation: Loss of 15 yards.
Note: The restrictions in (1) and (2) above do not apply if a team does not present a standard field goal or Try Kick formation (an equal number of players on either side of the snapper in a tight formation), or if, after the offensive team has assumed a set position, there is a shift, or a player goes in motion.
Rule 12 Player Conduct
ARTICLE 9. PLAYERS IN A DEFENSELESS POSTURE
It is a foul if a player initiates unnecessary contact against a player who is in a defenseless posture. A player who initiates contact against a defenseless opponent is responsible for avoiding an illegal act. A standard of strict liability applies for any contact against an opponent, even if his body position is in motion, and irrespective of any acts by him, such as ducking his head or curling up his body in anticipation of contact.
1. Players in a defenseless posture are:
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(12)The offensive player who attempts a snap during any scrimmage kick. He is no longer a defenseless player after he has had an opportunity to defend himself or moves downfield.
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https://operations.nfl.com/the-rules/nfl-rulebook/#rule9 ]
So this doesn't help me much. But, it's what I could find that appears relevant
Bears claim you can't make contact with longsnapper if his head is down. That doesn't make sense, every team would train their longsnappers to keep their heads down through the play to take away a middle charge.
So, we'll see