1. by touching the runner whom they believe committed a base running infraction (missed base or left before catch);
2. or by touching the base they believe was missed while the runner was advancing;
3. or by touching the original base that a runner left before a fly ball was caught.

In all cases a verbal appeal must be made to the umpire or an act that is unmistakably an appeal. Accidentally touching a base that was missed is not an appeal. A throw to a base to catch a runner who has not retouched is unmistakably an appeal.

Appeals must be made before the next pitch or play. If time has been called (or the ball is dead for any other reason. HR or foul ball etc.) and the defense makes an appeal, the umpire should say "put the ball in play and appeal again." Since no runner may advance or be put out while the ball is dead, this is not a play and the defense has not lost their right to appeal after the ball is put in play. The appeal itself is not a play. A fake throw to hold a runner is not a play. A balk committed during an appeal is a play. Plays that occur during continuous action after an infraction do not cancel the defenses right to appeal.

The defense loses their right to appeal when any of the following actions occur:

1. The throw to a base made in an appeal attempt goes into dead ball territory.
2. A balk is committed before or as part of an appeal attempt.
3. A pitch is made to the batter.
4. A play is made that is not part of continuous action.

Calling time prior to making an appeal does not cause the defense to lose their right to appeal. The ball must be put back in play by the pitcher stepping on the rubber with the ball and the umpire stating "Play." Then the appeal may be made.