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<DIV>Yes, but the set of subtags that appear in the Registry is not stable
either. New subtags can be added, causing a previously invalid tag to become
valid.</DIV>
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<DIV>Section 2.2.9 again: “Note that a tag's validity depends on the date of the
registry used to validate the tag. A more recent copy of the registry might
contain a subtag that an older version does not.”</DIV>
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<DIV>I’m not seeing why this applies to the presence or absence of a subtag in
the Registry, but not to the encompassing language relationship. I can live with
it, and will code to it, but it surprised me.</DIV>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri'; COLOR: #000000">--<BR>Doug
Ewell | Thornton, CO, USA<BR>http://ewellic.org | @DougEwell <BR></DIV>
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<DIV style="font-color: black"><B>From:</B> <A title=mark@macchiato.com
href="mailto:mark@macchiato.com">Mark Davis ☕</A> </DIV>
<DIV><B>Sent:</B> Monday, January 20, 2014 23:15</DIV>
<DIV><B>To:</B> <A title=doug@ewellic.org href="mailto:doug@ewellic.org">Doug
Ewell</A> </DIV>
<DIV><B>Cc:</B> <A title=ietf-languages@iana.org
href="mailto:ietf-languages@iana.org">mailto:ietf-languages@iana.org</A> </DIV>
<DIV><B>Subject:</B> Re: Validity</DIV></DIV></DIV>
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<P dir=ltr><BR>That's on purpose, since the encompassing language relationship
is not stable.</P>
<P dir=ltr>{phone}</P>
<DIV class=gmail_quote>On Jan 21, 2014 6:48 AM, "Doug Ewell" <<A
href="mailto:doug@ewellic.org">doug@ewellic.org</A>> wrote:<BR
type="attribution">
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">One
of the readily available test suites for BCP 47 tags shows "fr-fra" and
"fr-Lat" as valid tags. They aren't, of course, because Section 2.2.9
says:<BR><BR>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">A
tag is considered "valid" if it satisfies these conditions:<BR><BR>o
The tag is well-formed.<BR><BR>o Either the tag is in the list of
grandfathered tags or all of its<BR> primary language, extended
language, script, region, and variant<BR> subtags appear in the
IANA Language Subtag Registry as of the<BR> particular registry
date.<BR><BR>o There are no duplicate variant subtags.<BR><BR>o
There are no duplicate singleton (extension) subtags.<BR></BLOCKQUOTE><BR>and
the extended language subtags 'fra' and 'lat' do not appear in the Registry
(nor could they ever).<BR><BR>I was surprised, however, to see that a
combination of language and extlang subtags that don't match -- that is, the
language is not the Prefix for the extlang, as "ar-cmn" -- is perfectly valid.
In fact, the language subtag in such a pair doesn't even have to have its own
extlangs, so one could also write "fr-cmn" or "tlh-cmn" and a validating
processor would have to accept them. Does this surprise anyone
else?<BR><BR>--<BR>Doug Ewell | Thornton, CO, USA<BR><A
href="http://ewellic.org" target=_blank>http://ewellic.org</A> | @DougEwell
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