A kicker who has the skill to curl the ball around a wall is at a distinct advantage. Since 2000, referees at the highest levels of football have used vanishing spray to enforce the 9.15-metre (10-yard) minimum required distance for the wall; referees without vanishing spray may indicate the minimum distance verbally and/or with hand gestures. In 2019, Law 13 was changed to require attacking players to maintain a minimum 1-metre (1-yard) distance from a defensive "wall" until the ball is in play.[1]