The National Football League has narrowed its focus right down to the quarterback's passing arm in its latest concern about providing maximum safety for players.

In their annual meeting in March in Rancho Mirage, Calif., the club executives voted to make it illegal for an opponent to "strike, swing or club the passer's arm."

One rule change placed more severe restrictions on contacting a player's head, neck or face. Under the heading of a personal foul, players have been prohibited from directly striking, swinging, or clubbing on the head, neck or face.

Beginning this season, a penalty may be called for such contact whether or not the initial contact is made below the neck.

The interpretation of the quick whistle rule has been refined further to protect passers.

The area in which the passer is to be safeguarded when he is clearly in the grasp and control of any tackler will include anywhere behind the line of scrimmage (not just the passing pocket) and usually the area between the tight ends (when two are used on a play).

Head coaches again agreed not to teach the "help" block by running backs and tight ends attacking a defensive player below the knees while that player is engaged by another offensive player.

A timeout will not be charged to a team with an injured player if a foul committed by an opponent in the last two minutes of either half caused the injury.