Criteria for languages?

[Randy Presuhn]

Hi -

> From: "John Cowan" <cowan at ccil.org>
> To: "Peter Constable" <petercon at microsoft.com>
> Cc: <ietf-languages at iana.org>; "Doug Ewell" <doug at ewellic.org>
> Sent: Tuesday, December 01, 2009 9:29 AM
> Subject: Re: Criteria for languages?
...

> Peter Constable scripsit:
> 
> > If the denotation of "lav" were changed to explicitly exclude Latgalian
> > (which would be necessary if its scope is not set to macrolanguage),
> > then an unknown number of librarians will have broken data. It would
> > be irresponsible of the ISO 639-RA/JAC to do such a thing, IMO.
> 
> Quite so.
> 
> In that case, the issue for us is: do we recommend that people continue
> to use "lav" for Latvian proper, or that they adopt the new subtag?

If an application requires standard Latvian and Latgalian to be treated as distinct
languages, then clearly it would need to use the new subtag to identify standard
Latvian, since "lav" would mean "any kind of Latvian, including Latgalian".   This
is a natural consequence of our "no narrowing" rules - all of the data which is
currently precisely and accurately tagged as Latvian would remain accurately
tagged, though most would no longer be precisely tagged.  (Data for which the
tagger was unable to make a determination whether it was Latvian or Latgalian
would remain precisely tagged.)  The assumption is that it is better to introduce
a (potentially lingering) imprecision in the tagging of legacy data, rather than to
cause any once-accurate tags on legacy data to become incorrect.

Randy