USA is only country with two referees invited to World Cup referee seminar
(WorldNews Argentina)

U.S. referees Mark Geiger and Jair Marrufo were invited to take part in a seminar organized by the FIFA Referees Committee in Abu Dhabi as part of the preparations for the 2018 World Cup. The seminar, which ran five days and wrapped up on Wednesday, marked the start of the selection process for referees, assistant referees and video assistant referees for the 64 games. ......