Under the Grand Slam rules in tennis, coaching during the match is prohibited (ATP Code). It is a Code violation, and for the first code violation, players get a warning. Under those same rules, racket abuse is also prohibited.
i) Players shall not violently, dangerously or with anger hit, kick or throw a
racquet or other equipment within the precincts of the tournament site.
For purposes of this rule, abuse of racquets or equipment is deﬁned as
intentionally, dangerously and violently destroying or damaging racquets
or equipment or intentionally and violently hitting the net, court, umpire’s
chair or other ﬁxture during a match out of anger or frustration.
Racquet abuse could get a warning as well, but if it is the second code violation by a player during a match, the second violation would be a point losss.
Under the Code, Players may disagree with officials:
Responsible expressions of legitimate disagreement with ATP policies are not prohibited. However, public comments that one of the stated persons above knows, or should reasonably know, will harm the reputation or ﬁnancial best interests of a tournament, player, sponsor, oﬃcial or ATP are expressly covered by this section.
However, disagreement by players has its limits. For example, it is a Code violation for a player to engage in verbal abuse. Verbal abuse is defined under the code as “s statement about an official, opponent, sponsor, spectator, or other person that implies dishonesty or is derogatory, insulting, or otherwise abusive.”
For a first violation, players could receive a warning. For a second violation, players could lose a point. For a third violation in the same match, the penalty could be the loss of one game, which could mean the loss of a match.
In 2016, Carlos Ramos, a tennis umpire, issued a code violation to Andy Murray because he believed Mr. Murray had called him a “stupid umpire.” Murray responded that he had said, “Stupid umpiring,” and not “stupid umpire.” “Stupid” whether coupled with with “umpire” or “umpiring” is derogatory.
Serena Williams called Carlos Ramos a “liar” and a “thief” and also received a code violation. “Liar” and “thief” do not imply dishonesty. They are labels of dishonesty. She was given a one-game penalty, which Ms. Williams decried as unfair and an example of male players getting away with more than what she did. Actually, male players have been known to scream at refs, but they were not calling umpires “liars” and “thieves.” In fact, most penalties are assessed against men. As for the level of the penalties, it all depends on the number of the player’s violations per match. By the third code violation in the same match, an umpire could impose a warning, a one-point loss, or a one-game penalty. The application is not unfair. Sometimes cries of unfairness have resulted because of a lack of accurate information. Ms. Williams is comparing apples and oranges. Facts prove the umpire was correct and was just following the rules. New concept in this era.