Assistant referee (association football)
The additional assistant referee (AAR) is a match official who supports the main referee by standing behind the goal line. Their job is to help the referee watch for any incidents near the penalty area. In some cases, they've tried adding two more assistant referees positioned behind the goal lines. These extra officials were there to ensure that the rules of the game were followed, especially in important areas like the penalty area. They communicated with the referee through a wireless system and also helped in situations like "ghost goals." Experts from the International Football Association Board (IFAB) evaluated this trial. After testing it for two years in various competitions, including the UEFA Champions League and Europa League, IFAB officially approved the use of additional assistant referees in July 2012. They even used them in the 2013 Scottish Cup Final, marking the first time they were used in a Scottish domestic match.