[Torsten von Bayern]

Thank you Adham, I would like to confirm that it IS helpful. Faulty services can be produced deliberately or not, and the latter is more often the case than one might think.

When this happens, players should not think of the umpire as a person so untouchable that the player is not allowed to speak to him/her. The umpire is the person in charge of fair and structured match conduct. This includes making sure that the players know what they may do and what they may not. It is in nobody's interest that a player does a match being uncertain about a law or regulation. Therefore, as an umpire, I appreciate any calm and polite question of a player, because in responding to his/her question I can improve match conduct for ALL four parties: the two players or pairs, the spectators and the umpire.

It is of course the umpire's duty to distinguish between a real and an unfair question (for example in terms of when and how the question is made) - but this should be part of the umpire's training.