Thanks. I have used the "backward compatibility" term many times but never abbreviated it nor seen it abbreviated. The only idea that comes into my mind when I

Thanks. I have used the "backward compatibility" term many times but never abbreviated it nor seen it abbreviated. The only idea that comes into my mind when I see "BC" is "Before Christ" which actually feels pretty much relevant :-) Indeed they should really have spelled it out first and only used the uncommon abbreviation for subsequent occurrences.