draft-phillips-langtags-08, process, sp ecifications,
"stability", and extensions
singer at apple.com
Thu Jan 6 20:51:10 CET 2005
At 11:34 AM -0800 1/6/05, Peter Constable wrote:
> > From: Dave Singer [mailto:singer at apple.com]
>> >This is similar to the reason why the language code comes before the
>> >code. If we had the order CH-fr, then we could end up mixing French
>> >German in the same page, because we would fall back (for one of the
>> >sources) from CH-fr to CH, which could be German.
>> It has to be application-specific which fallback happens. If the
>> user says he's swiss french, and the the content has alternative
>> offers for swiss german or french french, which do you present? If
>> the content actually differs for legal or geographic reasons ('the
>> legal representative in your country is', 'for copyright reasons this
>> edition differs in material ways from other countries'), then the
>> correct country but wrong language is the best answer. If the desire
>> is simply for maximum intelligibility, then the reverse is true.
>But that is a level of decision making that goes well beyond any
>algorithm that simply uses truncation of tags, which is the only case in
>which the ordering of sub-tags matters.
Sorry, I should have gone on to conclude: the important aspect of
sub-tags is that their nature and purpose be identifiable and
explained (e.g. that this is a country code), and that we retain
compatibility with previous specifications. This tagging uses order
(and size) of sub-tags rather than explicit labels to say what
something is, and we're stuck with that. I don't believe that simple
truncation is a necessarily useful operation in all circumstances,
and it probably should not be in the spec. at all. For example, I'd
say that we should retain the 3066 ordering of language-country and
therefore script, if needed, comes later. However, my typesetting
subsystem doesn't care a jot about language or country, it just needs
to find the script code ('can I render this script'?).
This spec. should unambiguously allow me to extract the language,
country, script etc., should say under what circumstances two
sub-tags of any type match, state the obvious that two tags exactly
match if they have the same sub-tags and they all match, that partial
perfect matches (of tags with differing numbers of sub-tags) are
possible and may be applicable, and that the use of imperfect matches
(in which not all sub-tags match) has to be application-specific.
Examples of why on the latter would be helpful.
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