What are positional and rotational faults, and what are the Libero's attack limits?

From the FIVB Rules 2025-2028.

Positional fault (Rule 7.5): a team commits one if any player is not in the correct position when the server hits the ball. Positions are judged by the feet touching the floor. The consequence is a point and service to the opponent, and the positions are rectified. A serving fault at the moment of the service hit is counted before a positional fault. The 1st referee judges the serving team's positions and the 2nd referee judges the receiving team's.

Rotational fault (Rule 7.7): the service is not made in the rotational order. The scorer stops play with the buzzer, the opponent gains a point and the next service, and the faulty team's rotational order is rectified. The scorer should also work out the exact moment the fault happened, and all points the faulty team scored since then are cancelled (the opponent's points stay). If that moment cannot be determined, no points are cancelled and a point and service to the opponent is the only sanction.

Libero limits (Rule 19.3): the Libero may replace any back-row player, may not serve, block or attempt to block, and may not complete an attack hit from anywhere if the ball is entirely higher than the top of the net at contact. A player may not complete an attack hit on a ball entirely higher than the net if it comes from an overhand finger pass by the Libero in the Libero's front zone. The same ball may be attacked freely if the Libero makes that pass from outside the front zone.

Back-row players' attack hit and blocking faults are indicated by both referees.