@taldcroft - a bitmask is not necessary, as the status indicators are mutually exclusive. In particular, `FROM_IERS_A` and `FROM_IERS_B` indicate from which bulletin the values are taken, not from the type of table (which presumably the calling routine knows). Hence, if an IERS A table is used (which also contains IERS B values), the possible values are (ordered in time) `TIME_BEFORE_IERS_RANGE`, `FROM_IERS_B`, `FROM_IERS_A`, `FROM_IERS_A_PREDICTION`, and `TIME_BEYOND_IERS_RANGE`, while if an IERS B table is used, `FROM_IERS_A` and `FROM_IERS_A_PREDICTION` are not possible.