(b) A qualified referee or other suitably experienced person may be called upon in one of the following capacities.
(1) A Referee in Charge is a referee who is appointed by the Tournament Referee to take full charge of a match. Such a referee is to supervise all aspects of the match from taking the toss, starting actual play, maintaining the score, ensuring the match is played in accordance with these Laws and resolving any disputes that might arise. A Referee in Charge is also to ensure that any published regulations for a particular tournament that relate to the playing of the match are fully complied with. If requested, a Referee in Charge is to give players information about the progress of the game or an explanation of a Law, but is not to give advice to any player that is likely to assist the player in any way. A Referee in Charge is not to distract the players or to interfere with play, except to deal with breaches of the Laws, but should be suitably placed to verify the scoring of a point or the fairness of a stroke. A Referee in Charge is not to initiate action under Law 10.
(2) A Referee on Call is a referee who is summoned by a player to watch a stroke. While present, a Referee on Call has the same duties as a Referee in Charge. A Referee on Call is to first establish why the call was made and what the player intends to do, before taking an appropriate position to watch the stroke. Referees on Call are to remain on the court for the particular purpose requested and at their discretion thereafter. A request for a Referee on Call is not to be made if there is a Referee in Charge present.
(3) A Referee on Appeal is a referee who is asked by a player to give a decision on a matter of fact or about the Laws after an event has occurred. The referee's duties are the same as those of a Referee on Call. The matter is to be decided by observation or investigation or both. If the referee witnessed the event and need not investigate further, the players are to be so informed and the decision given. In other cases the referee is to decide the appeal after hearing both sides and, if necessary, other witnesses. If the referee observed something relevant the players are to be so informed. The decision is then to be given. In the last resort the referee may give a compromise decision. This may involve arbitrary adjustment of the score, which ball is next to play, the positions of the balls, the number of extra turns outstanding and the time remaining. The referee may decide that a game is to be restarted. Referees on Appeal are to remain on the court for the particular purpose requested and at their discretion thereafter. A Referee on Appeal is not to decide that a fault has been committed unless satisfied of the fact by personal observation or by the evidence of the offender or a Spectator Referee who personally observed the fault. A request for a Referee on Appeal is not to be made if there is a Referee in Charge present.
(4) A Spectator Referee is a referee who can only act when there is no Referee in Charge and whose powers and duties are confined to the following:
(i) To intervene to ensure that play is lawfully continued after a breach of the Laws is claimed or admitted.
(ii) To intervene if a player is heard giving erroneous information on the Laws or in response to a request under Law 8(b).
(iii) To intervene if a player is seen to claim a point when the hoop run is not the current hoop in order.
iv) To volunteer relevant information to a Referee on Appeal.
(v) To apply to the Tournament Referee to be appointed to a game.
(c) A player may appeal against a referee's application of the Laws but may not appeal against a referee's ruling on a matter of fact. Appeals are to be made to the Tournament Referee.