Courtesy runner in ITB

[Cecil4]

I sent info to a league coordinator, from the USA Softball Rules.
NFHS book just says States can adopt one.

A. Starting with the top of the eighth inning, and each half inning thereafter, the offensive team shall begin its turn at bat with the player who is scheduled to bat last in that respective half inning being placed on second base (e.g., if the number five batter is the lead off batter, the number four batter in the batting order will be placed on second base. A substitute may be inserted for the runner).

B. If a team is in the tie-breaker and the Short Handed Rule is in effect, do not declare an out if the absent player is the one who should begin the half inning at second base. Instead, place on second base the player whose name precedes the absent player’s name in the line-up. "

2) A clarification is that if the player placed on second base is the pitcher or catcher, they may have a Courtesy Runner.

3) You might hear/see this referred to as the ITB, because the original was known as International Tie Breaker, now TBR.