The 57+ Legends division rules are extended from the base rules here:

7. The batting line-up will consist of a minimum of 12 batters to a maximum of 18, Each Team in the ***(57+ Division will have an opportunity for 2 shared positions in the Batting Line-up. A Shared position is a such. (Example) if the 3rd batter indicated is chose to share a batter it will be indicated at 3A or 3B and can come to bat or run for each other providing the reach base when that turn comes up. These batters cannot bat for anyone else in the batting order and are not part of the designated runner rule unless (one or the other) is that last out (batter that was the batted / forced out) must run if the player after him requested a runner if he reach based.
***One note a Shared Position can only be implementated with 12 batters or more in Batting Order!

A substitution to the batting order may be made. Once a player is removed from the batting order, he may not return to the game in any playing capacity. (50 + and 57+ - this rule does not apply, all players on the roster can play defensively, and do not have to be a part of the batting lineup - however once removed from the batting lineup"minimum 12 / maximum 18" that player cannot be placed back into the batting order but still can play defensively). All possible participants for a game should be listed as extras on the line-up card.

10. A courtesy runner may be used. Batters requiring a courtesy runner must be designated prior to the game. The last out is to be the courtesy runner, unless he is also so designated, or is the catcher; go to the previous out. In 57+ the limited number of designated batters (4) will be permitted.

14 ***The Legend Division
Players must be 57 by Dec. 31 of the tournament year, 
Each team can have 3 players 55 by Dec 31 of the tournament yesr. One (and only one) can pitch and all must be highlighted on your team roster when handed in. The Legends' division players must have two items of identification, one with a photo for proof.