Say that Floofy (fl) and Fnord (fn) claim ownership of the large city of Fubar. I don't see anything wrong with putting Fubar in fl and fn. This way people in Floofy and Fnord see the city they expect to be there. And at the end of the day that's what tzinfo is for.
Logically, that makes sense, however geopolitically, people will figure out a way to object. The Fnordians would complain that Fubar doesn't belong in Floofy because it's part of Fnord. How would you or I feel if New York showed up in Canada? At the very least you'd report the bug. If the vendor pushed back on the bug, we'd probably push back with "what, are you crazy? NY is clearly in the US, not Canada." Geopolitics isn't about logic. That said, it might be possible in some cases to attach a city to two region codes. Or to create two cities for the same place.
My goal is to reduce the political debate on this list, and leave it to the diplomats and the standards committees that are under their control, to determine what is a country, and what city is in a country - then reflect those decisions in the database.
That works a bit. However it breaks down when someone wants to ship software that depends on the data. Then their customers push the same problems. And, note, that the IANA Timezone Database *IS* the standard, and we *ARE* the standard committee. It should be perfectly acceptable to point to ISO for the ISO standards though. The timezone data shouldn't pick & choose from other standards, if someone expresses a concern with another standard that the tzdb depends on, they should be pointed to the other standard to address it there. Worse, if someone objects to another standard's behavior, they could attempt to use the timezone effort to pressure the other standard, assuming they can get the timezone effort to see their viewpoint. IMO we should leave external standards alone, and focus on the timezone parts. A rather obvious alternate mapping would be to map to zones rather than cities, however that'd undoubtedly have it's own geopolitical problems. - Shawn