This section is from the book "Football For Player And Spectator", by Fielding H. Yost. Also available from Amazon: Football for Player and Spectator.
Umpire Has Jurisdiction. Movement Allowed Before Ball Is Put in Play.
Penalty, 5 yards, (a) Before the ball is put in play in a scrimmage, if any player of the side which has the ball takes more than one step in any direction, he must come to a full stop before the ball is put in play.
EXCEPTION - One man of the side having the ball may be in motion towards his own goal without coming to a stop before the ball is put in play.
Umpire Has Jurisdiction. Penalty, 5 yards.
(b) At least six men of the side holding the ball must be on the line of scrimmage. If not more than six men are on the line of scrimmage one man of those not on the scrimmage line must be outside the position occupied by the man on the end of the line. The line of scrimmage is an imaginary line parallel to the goal line and passing through the front point of the ball. A player shall be considered to be on the line of scrimmage if he has his head, his foot, or his hand up to or within one foot of this line. He must also, however, be outside the player next and between him and the snapper-back. In this rule "outside" means both feet outside the outside foot of the player next and between him and the snapper-back, as aforesaid.
Referee Has Jurisdiction. Penalty, 15 yards.
(c) The first man receiving the ball from the snapper-back may carry the ball forward, provided he crosses the line of scrimmage at least 5 yards outside of the point where the ball was snapped.
Suggestion. - This rule permits any player to run with a ball on a direct pass from center. So many teams get the idea that only quarter-backs may run on a direct pass.
 
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