They are technically called assistant referees.
They are called Rugby referees. They are assisted by 2 Assistant referees and a Television Match official (TMO)
as a minium 1 referee and 2 assistant referees.
They are the Assistant Referees
when six referees came to be.
Four. One in the center, two assistant referees, and one fourth official.
players, match officials, Referees, assistant referees, stewards
They were previously called Linesmen, now they are officially called Assistant Referees, or Referee's Assistants.
below regional level there are 3 - The referee and 2 assistant referees At Regional level there is a Referee, 2 assistant referees and a TMO (Television Match Official)
at senior level (regional ) there is One referee and 2 assistant referees plus a TMO (TV match official) In non regional there is One referee and 2 assistant referees
The duties of an assistant referee are explained in Law 6 of the FIFA Laws of the Game. Basically, Assistant Referees are there to help the Referee.