ref_codes.json

{
  "codes_0": [[100, 200, 300, 400]],
  "codes_1": [[10, 20, 30, 40, 50, 60, 70, 80]],
  "codes_2": [[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]]
}