Does the Clock Start on the Ready or Snap

[Theisey]

NF: we've covered this territory before very early in the year either here or those other forums.

See case book play 3.4.3 Sit-A (a)
Yes, there are no fouls in that play, but the words are the clocked was stopped because of the fair catch.
That alone was the action the really caused the down to end and it stopped the clock.

Same play but what if the scrimmage kick went OOB? Clocked was stopped for that. Penalties offset, clock starts on the Snap. Same play, make it roughting the passer and the pass is incomplete... penalties offset, clock starts on the snap.