When creating Between mappings, ensure that the sides of the mapping range are the same length. For example: 2000.000, 2991.999 is a valid mapping, and 2000.000, 2991 is not a valid mapping. This caution is especially important if a mapping excludes accounts. For example, 2000.000, 2991 excludes 2991.000 through 2991.999.
Additionally, Between mappings must be the same length to ensure that accounts use the correct map. For example: If the mapping 1530, 1540 and the mapping 1530000, 1540000 both exist, the account 1540 is imported by the second mapping (1530000, 1540000).