At the moment of the serve, what players must be in the correct serving order?

At the moment of the serve, it is essential that all players on the court, including the libero, are positioned in accordance with the predetermined serving order. This order must be adhered to strictly, as violations can lead to penalties during the match.

The rationale behind requiring all players to be in the correct serving order is to maintain the structure and fairness of gameplay. It ensures that each team's strategy, including potential rotations and substitutions, is respected and systematically followed. Each player is assigned a specific rotational position, and any deviation from this can disrupt the flow of the game.

The libero, while having specific rules regarding substitutions and position on the court, is still considered part of the team's lineup for the purpose of serving order. Thus, it is imperative that even this specialized player is accounted for when the serve occurs. This adherence upholds the integrity of the match and allows for proper officiating.