They used to be called linesmen but now they're referee assistants and they help the referee with offside decisions and signal a number of things, such as throw-ins and substitutions. If the manager ...

But the type of signal is dependent on where the offside offence is committed. The position where the assistant holds his flag makes it clear to the referee, players and spectators which player is ...

Law 5: The Referee - powers and duties, Video Assistant Referee (VAR), referee's equipment, referee signals… Law 6: The Other Match Officials - assistant referees, fourth official, assistant ...

Other match officials (two assistant referees, a fourth official, two additional assistant referees, a reserve assistant referee, a video assistant referee (VAR) and at least one assistant VAR (AVAR)) ...

During a competitive game of football there is a referee and two assistant referees ... but acts as an additional referee and signals if they observe an infringement of the Laws.