Chart: Modified NFL football rules

• Teams will be able to supply their own footballs, but the kicking game coordinator will take custody once they have been approved by officials.

• Before a game, two members of the officiating crew will inspect the footballs, number them and record PSI data. The footballs need to measure between 12.5 and 13.5 PSI; if they don't, they'll be adjusted to 13.0 PSI.

• Ten minutes before the game, the coordinator, a member of the officiating crew and a security person will bring 24 approved game balls (12 for each team) to the on-field replay station for distribution.

• At some games, footballs will be randomly checked at halftime and after the game, and PSI data will be recorded to determine how cold weather affects the footballs.