As you may remember, there was a discussion on the Unicode list last
month about the ISO 3166 Maintenance Agency changing the 3-letter
country code for Romania from ROM to ROU.  The request to make this
change was made by the Romanian government, but no specific rationale
was provided, and some conjectured it had to do with shunning the
abbreviation "ROM," the Romanian word for "gypsy."

A few of us worried about the "stability" of a standard in which codes
could be changed at the request of a single body.  We contrasted it with
the Unicode and ISO/IEC JTC1/SC2/WG2 policy of never changing the names
or positions of coded characters, for the sake of interoperability and
compatibility.

Recently, for a totally unrelated reason, I requested a copy of the list
of ISO 3166 "Reserved Code Elements" from the ISO 3166/MA.  These are
codes that the ISO 3166/MA has pledged not to allocate because of the
potential for confusion or interoperability problems.  The list provides
quite an interesting supplement to the regular ISO 3166 code lists.

There are three types of reservations:

1.  transitional, generally used for countries that have recently
changed names or ceased to exist.

2.  indeterminate, generally used to avoid conflicts with non-3166
symbols on automobile ID stickers.

3.  exceptional, usually made at the request of a specific country or
body to avoid conflicts and confusion (e.g. the United Kingdom ("GB")
asked for "UK" to be reserved).

Under the category of "indeterminate" reservations, the list refers to
the 1949 and 1968 UN Conventions on Road Traffic, which established the
use of country codes for little white elliptical stickers on rear
bumpers, and states, "Any use [of these codes] beyond the application of
the two Conventions is discouraged and will not be approved by the ISO
3166/MA."  Now, can you guess what one of these reserved codes is?

Ah, you're too smart.  That's right, ROU.

ROU is listed as an "indeterminately reserved alpha-3 code element" for
Uruguay.  One can presume that this is a road-vehicle abbreviation for
Rep├║blica Oriental del Uruguay (a legend that has appeared on Uruguayan
coins for at least a century).  In any case, it turns out that ISO
3166/MA has not only changed a country code element, potentially
breaking some application or usage that depended on the stability of the
standard, but changed it to another code that the MA has already listed
as reserved, saying in effect "we promise not to use this code for
anything."

This would be like the Unicode Standard not only moving an encoded
character to a different code point, but moving it to one of the
noncharacter code points (such as U+FDD0).

As Ken Whistler pointed out last month, ISO 3166 was intended more for
bibliographic purposes than for computer applications, so the policy of
"once encoded, set in stone" that works for Unicode does not apply
equally to ISO 3166.  But a policy of explicitly reserving codes for
non-use, publishing the list (even if it has to be specially requested),
and then turning around and using a code from that list, without an
*extremely* compelling and publicly stated justification, can't be a
good thing.  Standardizers, please learn a lesson from this.

-Doug Ewell
 Fullerton, California



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