USTA Comment 3.1: May a player cause a ball to become wet by using the ball to wipe perspiration from the player’s body? No. A player may not take any action that materially changes the condition of the ball; therefore, a player may not use a ball to wipe off perspiration.
The Racket
Case 3: Can vibration damping devices be placed on the strings of a racket? If so, where can they be placed?
Decision: Yes, but these devices may only be placed outside the pattern of the crossed strings
Ball Touches a Pernament Fixture
USTA Comment 13.1: What happens if a ball hits an object attached to the net or post (such as a scoring device) or the top of the net outside the singles stick and then lands in the court? The player who hit the ball loses the point because it hit a permanent fixture before landing in the court.
Service Fault
Case 1: After tossing a ball to serve, the server decides not to hit it and catches it instead. Is this a fault?
Decision: No. A player, who tosses the ball and then decides not to hit it, is allowed to catch the ball with the hand or the racket, or to let the ball bounce.
When to Server nad Receive
The server shall not serve until the receiver is ready. However, the receiver shall play to the reasonable pace of the server and shall be ready to receive within a reasonable time of the server being ready. A receiver who attempts to return the service shall be considered as being ready. If it is demonstrated that the receiver is not ready, the service cannot be called a fault.
The Let During a Serve
The service is a let if:
a. The ball served touches the net, strap or band, and is otherwise good; or, after touching the net, strap or band, touches the receiver or the receiver’s partner or anything they wear or carry before hitting the ground; or
b. The ball is served when the receiver is not ready
The Let
Case 1: When the ball is in play, another ball rolls onto court. A let is called. The server had previously served a fault. Is the server now entitled to a first service or second service?
Decision: First service. The whole point must be replayed.