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.