Off-court coaching will be allowed in tennis from January 2025, the International Tennis Federation (ITF) has announced.
The decision was made at the governing body's annual general meeting and follows recent trials on the men's ATP and women's WTA tours.
The ITF says the move will make tennis "fairer and, potentially, more entertaining".
The new changes mean:
Coaches can issue advice either verbally or via hand signals at any time except during the playing of a point.
Coaching must be "brief and discreet", except during breaks in play.