ISO/IEC
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... encoding. Up to the
present time, changes in Unicode and amendments to ISO/IEC 10646 have
tracked each other, so that the character repertoires and code point
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...
UTF-1 has only historical interest, having been removed from ISO/IEC
10646. UTF-7 has the quality of encoding ...
... octets, where the number of octets, and the value of each, depend on
the integer value assigned to the character in ISO/IEC 10646. This
transformation format has the following characteristics (all values
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...
ISO/IEC 10646 is updated from time to time by published amendments;
similarly, different versions of the Unicode ...
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In general, the changes amount to adding new characters, which does
not pose particular problems with old data. Amendment 5 to ISO/IEC
10646, however, has moved and expanded the Korean Hangul block,
thereby making any previous data containing Hangul characters invalid
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... media types
containing text consisting of characters from the repertoire of
ISO/IEC 10646 including all amendments at least up to amendment 5
(Korean block), encoded to a sequence of octets using the encoding
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... UTF-8" does not contain a version
identification, referring generically to ISO/IEC 10646. This is
intentional, the rationale being as follows:
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Now the "Korean mess" (ISO/IEC 10646 amendment 5) is an incompatible
change, in principle contradicting the appropriateness of a version
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... Hangul characters encoded according to Unicode 1.1 (or equivalently
ISO/IEC 10646 before amendment 5), and there is arguably no such data
to worry about, this being the very reason the incompatible change
was deemed acceptable.
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... and provided no incompatible change actually occurs. Should
incompatible changes occur in a later version of ISO/IEC 10646, the
MIME charset ...
... containing Hangul syllables encoded to UTF-8 without taking into
account Amendment 5 of ISO/IEC 10646 (i.e. using the pre-amendment 5
code point assignments). Any other UTF-8 ...
... particular data not containing any Hangul syllables, and it
is felt important to strongly recommend against creating any new
Hangul-containing data without taking Amendment 5 of ISO/IEC 10646
into account.
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... ISO/IEC 10646-1:1993. International Standard -- Information technology -- Universal Multiple-Octet Coded Character Set (UCS) -- Part 1: Architecture ...