Only 1 player on the right flank! as Dv8r said earlier no more than 2 on either flank, but must be at least 1 on each flank.
4 positions on left side are DL - DML - ML - AML
4 positions on right side are DR - DMR - MR - AMR
You can only choose no more than 2 each side, but you must select 1 of the positions.