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Re: UTF-7 and java

From: A. Vine <avine@eng.sun.com>
Date: Tue, 28 Aug 2001 12:09:43 -0700
To: Barry Caplan <bcaplan@i18n.com>, www-international@w3.org
Message-id: <3B8BEC77.E00DF27A@eng.sun.com>
I just want to clear up a few things about mail:

Headers are purportedly restricted to 7-bit (RFC 822, Section 3.1.2).  This is
not always adhered to, especially in the Subject header and comments in the To,
From, Cc headers.  Many Japanese use mail clients which do not follow MIME
standards, as I have discovered.  I believe this is not uncommon in Asia.

RFC 1468 - Japanese Character Encoding for Internet messages, ISO-2022-JP for
Japanese emails, covers JIS X 0201 (except no half-width katakana) and JIS

RFC 1557 - Korean Character Encoding for Internet messages, ISO-2022-KR plus
EUC-KR, that is, ISO-2022-KR for the body, EUC-KR for the headers, this is an
informational RFC.  Of course, in MIME, the headers would be formatted using RFC
2047 encoded-words.

RFC 1922 - Chinese Character Encoding for Internet messages, ISO-2022-CN, this
is meant to include both the 1st 2 planes of CNS11643 (roughly, Traditional
Chinese Characters) and GB2312 (roughly, SImplified Chinese Characters) using
not just escape sequences but also shift states.  It is complex to use, and
therefore is not often seen.  It, too, is an informational RFC.

RFC 2237 - Japanese Character Encoding for Internet messages, ISO-2022-JP-1,
similar to ISO-2022-JP but adds a new escape sequence which includes JIS X
0212.  It is an informational RFC.  I have never encountered this charset.

IMAP folder names are in Modified UTF-7, which is not the same as UTF-7.  Yes,
it is similar, but in programming, similar doesn't work.

If you want to read an RFC, they are always available at:


where NNNN is the number of the RFC, and is variable length.  So, for example,
you can read RFC 822 at http://www.ietf.org/rfc/rfc822.txt and RFC 1468 at
http://www.ietf.org/rfc/rfc1468.txt .

iPlanet i18n architect
"The devil is in the details, folks."
Received on Tuesday, 28 August 2001 15:11:05 UTC

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