For Boys & Girls:

• The line of scrimmage for the offense is a vertical plane through the point of the ball nearest that team's goal line. The line of scrimmage for the defense is 1 yard beyond the vertical plane through the point of the ball nearest that team's goal line.
• The player in position to receive the snap must be a minimum of 2 yards behind the snapper.
• There are no restrictions on “running up the middle”. 

For Girls only:

• Screen blocking is taking position to obstruct the path of an opponent without contacting the opponent with any part of the blocker’s body.  
• Blocking by any player is illegal unless it is a screen block.
• After assuming a legal position, a screen blocker may move to maintain legal position by moving in the same direction or path as the opponent. Screen blocking shall take place without initiating contact during the process of the block. A screen blocker shall not extend the arms, or use hands, arms, elbows or legs to initiate contact.
• A defensive player may not:
  • Initiate contact with an opponent.
  • Initiate contact with an eligible receiver.