My wife was playing a match and got into an argument with her opponent. My wife called a ball out and her opponent disagreed. My wife confirmed her call. When changing sides, her opponent yelled at her and basically called her a cheater. My wife conceded the match and left the court rather than be abused. This was a USTA League Tennis match and my wife's team wants to file a grievance, but we're having trouble finding a specific section of "The Code" that was violated. "The Code" is clear that the line call was my wife's to make and the opening section mentions avoiding unsportman-like conduct like yelling, racket abuse, etc, but is there anything else?