language tag
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... The Language tag ...
... Language tag syntax ...
...
The language tag is composed of one or more parts: A primary language
subtag and a (possibly empty) series of subsequent subtags.
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... Language tag sources ...
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The namespace of language tags is administered by the Internet
Assigned Numbers Authority (IANA) [RFC 2860 ...
... country codes AA, QM-QZ, XA-XZ and ZZ as user-
assigned codes. These MUST NOT be used to form language tags.
...
... Choice of language tag ...
... You SHOULD NOT use the UND (Undetermined) code unless the protocol
in use forces you to give a value for the language tag, even if
the language is unknown. Omitting the tag ...
... Meaning of the language tag ...
...
The language tag always defines a language as spoken (or written,
signed or otherwise signaled) by human beings for communication of
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... NOTE: This use of a prefix matching rule does not imply that language
tags are assigned to languages in such a way that it is always true
that if a user understands a language ...
... IANA registration procedure for language tags ...
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The procedure given here MUST be used by anyone who wants to use a
language tag not given an interpretation in chapter 2.2 of this
document or previously registered with IANA.
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... ----------------------------------------------------------------------
LANGUAGE TAG REGISTRATION FORM
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When the two week period has passed, the language tag reviewer, who
is appointed by the IETF Applications Area Director ...
... registrations follow the same procedure as registrations.
The language tag reviewer decides whether to allow a new registrant
to update a registration ...
... language or in that language may be appropriate. The
language tag reviewer decides what constitutes a "good enough"
reference material.
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...
The only security issue that has been raised with language tags since
the publication of RFC 1766(-> 3282draft | 3066(-> 4647 | 4646)), which stated that "Security issues ...
...
Language tags may always be presented using the characters A-Z, a-z,
0-9 and HYPHEN-MINUS, which are present in most character sets, so
...
... 0-9 and HYPHEN-MINUS, which are present in most character sets, so
presentation of language tags should not have any character set
issues.
...
... The issue of deciding upon the rendering of a character set based on
the language tag is not addressed in this memo; however, it is
thought impossible to make such a decision correctly for all cases
unless means of switching language ...
...
Special thanks must go to Michael Everson, who has served as language
tag reviewer for almost the complete period since the publication of
RFC 1766(-> 3282draft | 3066(-> 4647 | 4646)), and has provided a great deal of input to this revision.
...
... Appendix A: Language Tag Reference Material ...
... Added numbers to the permitted characters in language tags ...