Why alpha4 codes? [was: RE: Question on ISO-639:1988]

[Lee Gillam]

RFC 3066 specifies where codes come from, and the length used for
them, although it is necessary to refer to that particular part of
the specification in order to make the association. If one assumed 
that any 2 letter code came from some place, or a certain 2 letters
were language or region, without following such a specification, 
this pronouncement does indeed hold. The specification provides
a means to distinguish e.g. 2 different sets of alpha2 codes:

   The tags and their subtags, including private use extensions, are to
   be treated as case insensitive: there exist conventions for the
   capitalization of some of them, but these should not be taken to
   carry meaning. For instance, [ISO 3166] [4] recommends that country
   codes be capitalized (MN Mongolia), while [ISO 639] [3] recommends
   that language codes be written in lower case (mn Mongolian). In the
   language tags defined by this document, however, the tag 'mn-MN' is
   not distinct from 'MN-mn' or 'mN-Mn' (or any other combination) and
   each of these variations conveys the same meaning: Mongolian for
   Mongolia.

To determine which "mn" is which in mn-mn cannot be done by assumption,
one should follow the specification.

If order and length can be appropriately specified, confusing 2- 3- or
4- letter codes for various subparts should be avoidable, which was the
essence of the original post.

> > I would suggest that making an assumption of where a specific code
> > of any length originates from is somewhat flawed. 
> 
> Please read or reread RFC 3066 (which this list is about) before making
> such pronouncements.
> 
> -- 
> John Cowan                              jcowan at reutershealth.com
> http://www.ccil.org/~cowan              http://www.reutershealth.com
> Thor Heyerdahl recounts his attempt to prove Rudyard Kipling's theory
> that the mongoose first came to India on a raft from Polynesia.
>         --blurb for Rikki-Kon-Tiki-Tavi