What counts as flag guarding, and can ball carriers jump or spin?

Flag guarding is any attempt by the ball carrier to block a defender's access to the flags: stiff-arming; dropping the head, hand, arm, elbow or shoulder; using the ball as a shield; or intentionally covering the flags with the jersey. Jerseys must be tucked in before play, and deliberately obstructed flags count as flag guarding. Penalty: -5 from the spot and loss of down.

Jumping and hurdling: runners can't jump, leap, dive or hurdle while advancing the ball. Blow the play dead and spot the ball where the jump happened. Players may dive to catch a pass or pull a flag.

Allowed without stopping play: spins, jump cuts, a QB leaving their feet to pass, or a runner leaving the ground clearly to avoid a collision. If illegal contact happens while airborne, you can still penalize it.

Charging: a ball carrier running directly into a set defender, including leading with the head or contacting with the shoulder, forearm or chest, is -5 from the spot and loss of down. Ball carriers must try to avoid defenders with established position.