Language subtag registration for acor1971

[Frank Ellermann]

2011/8/22 João Miguel Neves:

> Subtag: acor1971

Out of curiosity, the years you are interested in are apparently still
available, wouldn't it be better to use subtags 1971 and 1990, or just
the same style xyz1971 and xyz1990 instead of different acor1971 vs.
ao1990 styles?  I'd likely confuse acor vs. ao before I get this right.

-Frank