[tz] [PATCH] Revert recent pre-1970 changes.

[Paul Eggert]

Stephen Colebourne wrote:
>>> >> The Theory change reinstates the one zone per ISO-3166
>>> >> region requirement.
>> >
>> > I'm afraid that's incorrect.  That change would strengthen
>> > the requirement beyond what it ever was, by requiring a Zone
>> > to be present for every country.  That has never been
>> > required and has never been the practice in the tz database.

> You are mistaken.

Hmm, in reviewing the changes it appears we are both
mistaken.  The older guideline, which you are proposing to
resurrect, does not require "one zone per ISO-3166 region";
it allows a link instead of a zone, and it doesn't require
either for uninhabited regions.  I relied on your summary of
the change rather than looking at the actual wording.  So
when I wrote "has never been the practice", I was referring
to the fact that it's always been the case that some country
codes have links and not zones, while the uninhabited ones
have neither.

Since we do not remove names, and we already cover the
inhabited ISO 3166 codes, the only reason to resurrect the
older guideline would be to commit ourselves to the creation
of a new link or zone in response to a new country code, or
an existing one that becomes inhabited.  Say, for example,
the UN headquarters declares independence so the folks at
ISO 3166 decide to add a code UN for the United Nations, or
suppose the United States splits apart into the Red States
and the Blue States.  In either case, we shouldn't commit
ourselves to creating new zones or links in response to
these political developments.  If the old names continue to
work, there's no timekeeping reason to change them, and we
should insulate our maintenance guidelines from politics as
much as we can.