What's the mercy rule, and who signs off on the final score?

Mercy rule: in regular-season play the game ends when one team leads by 35 points or more. The teams can agree to keep playing without changing the score. (Tournaments use 28 points.)

Forfeits are scored 35-0 (28-0 in tournaments).

Score sheet: the coaches, officials and scorekeeper must verify the score sheet. If a coach leaves the field without verifying it, the scorekeeper notes that on the sheet and the score is final.