Down-by-contact: It is a permanently reviewable play for game officials.

Spiking the ball: Players who spike or throw the ball after a play (other than a touchdown) will draw a 5-yard penalty. "We did not think this type of spiking was good for sportsmanship or the administration of the game by officials," McKay said.

Player safety: It is now a 15-yard penalty (up from 5 yards) for a player to make a block below the waist of an eligible receiver while the quarterback is in the pocket.

Crowd noise: The 5-yard penalty against the defense for excessive crowd noise has been eliminated; it had not been called for many years.

Clock stoppage: Instant replay review prior to the two-minute warning will reset the play clock at 25 seconds, as will an instant replay review after the two-minute warning that results in a reversal.

10-second runoff: The 10-second runoff inside the two-minute warning will occur no matter the score of the game. The defense has the option to decline to 10-second runoff to maintain time should its offense get the ball back.

Pace of game: The foul for the unintentional touching of a forward pass by an offensive lineman has been eliminated.

There are three points of emphasis for game officials:

Illegal contact and defensive holding will continue to be strictly enforced. After 5 yards, if a receiver tries to avoid a defender, the defender can't make contact with the receiver if the quarterback is in the pocket with the football.

In previous seasons, an airborne runner had to get just any part of his body inside or over the goal-line pylon. It was not consistent with how the ball was spotted elsewhere on the field, McKay said. Now an airborne runner must get any part of the football inside or over the goal-line pylon before he touches out of bounds in order to be rewarded the score.

Taunting will continue to draw a 15-yard penalty and will be strictly enforced.