A standard for designating cities in intersystem data exchange?

Question

ISO

I want to develop a system that gives certain information about the city (the city can be in any country). I expect other systems to connect to my system using the API.
How do I identify cities? What are the standards on this subject and how widely are they used?
And where can I get a description of these standards?

Answer 1

Decided to use IATA codes :
betravel.ru/iata-country-list.php

Answer 2

You can use the WOEID system offered by Yahoo and used by Twitter
en.wikipedia.org/wiki/WOEID
developer.yahoo.com/geo/placemaker/habrahabr.ru/blogs/webdev/25315/

Answer 3

You can use OKATO codes, they are used in banking and accounting

Answer 4

You can use KLADR to the settlement. Or use the zip code (primary).

Answer 5

the only thing I can offer international, besides airport codes, is telephone prefixes of
cities

Answer 6

You can also use latitude and longitude. Inconvenient, but reliable :)