Likewise, what is the ruling when your serve, before touching the ground, hits an opponent who is standing back of the baseline.
All players have a responsibility to be familiar with the basic rules and customs of tennis.
Ignorance of the rules constitutes a delinquency on the part of a player and often spoils an otherwise good match. What is written here constitutes the essentials of The Code shall apply in cases not specifically covered by The Rules of Tennis and USTA Regulations. There are a number of things not specifically set forth in the rules that are covered by custom and tradition only. For example, if you have a doubt on a line call, your opponent gets the benefit of the doubt. Further, custom dictates the standard procedures that players will use in reaching decisions.