The refereeing corps for a match is composed of the following officials:
the first referee (Rule 23)
the second referee (Rule 24)
the challenge referee (Rule 25)
the reserve referee (Rule 26)
the scorer (Rule 27)
four (two) line judges (Rule 28)
Their location is shown in Diagram 10.
Volleyball Canada - For competitions using the Libero rule, an assistant scorer is necessary to monitor that the Libero replacement is legal.
22.2.1 Only the first and second referees may blow a whistle during the match:
22.2.1.1 the first referee gives the signal for the service that begins the rally;
22.2.1.2 the first or second referee signals the end of the rally, provided that they are sure that a fault has been committed and they have identified its nature.
22.2.2 They may blow the whistle when the ball is out of play to indicate that they authorize or reject a team request.
22.2.3 Immediately after the referee’s whistle to signal the completion of the rally, they have to indicate with the official hand signals (Rule 22.2.1.2, 28.1)
22.2.3.1 If the fault is whistled by the first referee, he/she will indicate in order:
a) the team to serve
b) the nature of the fault
c) the player(s) at fault (if necessary)
Volleyball Canada – In domestic youth competition environment, the second referee will follow the first referee’s hand signals by repeating them.
22.2.3.2 If the fault is whistled by the second referee, he/she will indicate:
a) the nature of the fault
b) the player at fault (if necessary)
c) the team to serve following the hand signal of the first referee.
In this case, the first referee does not show either the nature of the fault or the player at fault, but only the team to serve.
22.2.3.3 In the case of an attack hit fault or blocking fault by back row or Libero players, both referees indicate according to 22.2.3.1 and 22.2.3.2 above.
22.2.3.4 In the case of a double fault both referees indicate in order:
a) the nature of the fault
b) the players at fault (if necessary).
The team to serve next is then indicated by the first referee.