Are the board positions of the 4 players of each country determined by Elo rating in chess olympiads? Are the board positions of the 4 players of each country determined by Elo rating in chess olympiads? Or is this something arbitrarily decided by the countries?

By board positions I mean, 1st seed/board, 2nd seed/board, 3rd seed/board and 4th seed/board.
I do remember seeing some players with higher Elo ratings sitting on lower boards, hence I am wondering what the regulations are.
Look for fixed board order in the FIDE handbook's Regulations for the Chess Olympiad. The essence is that the board order cannot be changed between rounds for the purpose of getting a strategic advantage.