APPENDIX K ITF RULES OF TENNIS The chair umpire or referee shall make decisions regarding continuous play and  coaching in respect of any Code of Conduct that is approved and in operation. Case 1:  The chair umpire awards the server a first service after an overrule, but  the receiver argues that it should be a second service, since the server  had already served a fault. Should the referee be called to court to give a  decision? Decision:  Yes. The chair umpire makes the first decision about questions of tennis  law (issues relating to the application of specific facts). However, if a player  appeals the chair umpire’s decision, then the referee shall be called to make  the final decision. Case 2:  A ball is called out, but a player claims that the ball was good. May the  referee be called to court to make a decision? Decision:  No. The chair umpire makes the final decision on questions of fact (issues  relating to what actually happened during a specific incident). Case 3:  Is a chair umpire allowed to overrule a line umpire at the end of a point if, in  the chair umpire’s opinion, a clear mistake was made earlier in the point? Decision:  No. A chair umpire may only overrule a line umpire immediately after the  clear mistake has been made. Case 4:  A line umpire calls a ball “Out” and then the player argues that the ball was  good. Is the chair umpire allowed to overrule the line umpire? Decision:  No. A chair umpire must never overrule as the result of the protest or appeal  by a player Case 5:  A line umpire calls a ball “Out”. The chair umpire was unable to see clearly,  but thought the ball was in. May the chair umpire overrule the line umpire? Decision:  No. The chair umpire may only overrule when sure that the line umpire  made a clear mistake.  Case 6:  Is a line umpire allowed to change the call after the chair umpire has  announced the score? Decision:  Yes. If a line umpire realises a mistake, a correction should be made as soon  as possible provided it is not as the result of a protest or appeal of a player. Case 7:  If a chair umpire or line umpire calls “Out” and then corrects the call to  good, what is the correct decision? 469