More on Rule 7: Snapping, Handing, and Passing the Ball

The Numbering Exception is under 7-2-5b: Basically, on a scrimmage kick, any player(s) #'d 1-49 or 80-99 can take the place of any player(s) #'d 50-79 on the line, but they are ineligible receiver(s).

The FumbleRooski Killer is Rule 7-2-8 (or at least that's the way I read it): Any "A" player on LOS can't advance a planned loose ball in the vicinity of the snapper.

The matter of fumble out of bounds in the end zone is addressed in 7-4-4: A fumble or backward pass that goes OOB behind the hoal belongs to "B" as a touchback or safety, depending on which goal it is.