American Football NCAA Rule 10-2-5-a

a. Fouls by the nonscoring team during a down that ends in a touchdown (not on the try).
1. Fifteen-yard penalties for personal fouls and for unsportsmanlike conduct fouls are enforced on the try, the succeeding kickoff or from the succeeding spot in extra periods at the option of the scoring team.
2. Five- and 10-yard penalties are not enforced on the try or the succeeding kickoff. Such penalties are declined by rule unless enforcement is made possible by illegal touching of a kick during the down (A.R. 6-3-2-IIIIV).