def set_significant_digits(radar) -> None:
    """
    Set _Least_significant_digit netcdf attribute.
    """
    fieldnames = [
        ("VEL", 2),
        ("VEL_UNFOLDED", 2),
        ("DBZ", 2),
        ("DBZ_CORR", 2),
        ("DBZ_CORR_ORIG", 2),
        ("RHOHV_CORR", 2),
        ("ZDR", 2),
        ("ZDR_CORR_ATTEN", 2),
        ("PHIDP", 4),
        ("PHIDP_BRINGI", 4),
        ("PHIDP_GG", 4),
        ("PHIDP_VAL", 4),
        ("KDP", 4),
        ("KDP_BRINGI", 4),
        ("KDP_GG", 4),
        ("KDP_VAL", 4),
        ("WIDTH", 4),
        ("SNR", 2),
        ("NCP", 2),
        ("DBZV", 2),
        ("WRADV", 2),
        ("SNRV", 2),
        ("SQIV", 2),
    ]
    # Change the temporary working name of fields to the one define by the user.
    for key, value in fieldnames:
        try:
            radar.fields[key]["_Least_significant_digit"] = value
        except KeyError:
            continue

    return None