Paul Eggert wrote on 1998-10-02 20:51 UTC:
True, but the 2-letter country codes are _much_ better known (especially now that they're part of Internet domain names), and they are much more common in most application areas served by POSIX and the ISO C standard. If you're going to use an ISO-based approach for locations, then the 2-letter codes are clearly the way to go.
The 3-digit codes are not stable either, as locations change hands (the breakup of the Soviet Union being a recent example of wholesale reassignments). Since complete stability is impossible, we have to judge whether the 3-digit codes' slight increase in stability compensates for the increased number of user (and/or programmer) errors that are inevitable with numerical codes. In my view, the tradeoff is decisively in favor of the familiar alphabetic codes.
The numeric and alpha codes have very different purposes: the alpha code identifies more or less the name of a country, while the numeric code identifies its territory. Identification of the territory is highly relevant for statistical applications, because per-country statistics become incomparable if the territory changes (see German reunification as a good example). The ISO 3166 numeric codes are just the codes used by the UN statistics office. Identification of the territory of countries might actually be slighly more relevant to tz applications than identifications of names of countries (see also the hacks related to "mainland France"). Markus -- Markus G. Kuhn, Security Group, Computer Lab, Cambridge University, UK email: mkuhn at acm.org, home page: <http://www.cl.cam.ac.uk/~mgk25/>