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Re: Registration of new charset CP50220
(2010/04/22 1:21), Masatoshi Kimura wrote:
>> 13 JIS X 0201-Katakana ESC ) I G1
> Is there any implementaions which actually support this sequence?
> At least Mozilla implementation doesn't. It doesn't support SI/SO either.
Internet Explorer and Opera support 8-bit Katakana.
Internet Explorer supports Shift-in Katakana.
http://coq.no/character-tables/mime/iso-2022/en
>> Another typical user is Japanese IRC network. They sometimes send
>> JIS X 0201-Katakana encoded in GR (JIS8).
> What does it mean? You said this charset is 7-bit encoding.
>
>> Since the "CP50220" is 7bit encoding, Content-Transfer-Encoding is
>> not needed.
>> Based64 or Quoted-Printable encoding MAY break this encoding.
>> This charset is ISO/IEC 2022 family.
> For these reasons, I don't think it's appropriate to treat this charset
> as an ISO/IEC 2022 family.
Hmm you are right, I removed 8-bit and Shift-in Katakana.
And I added following line:
* CP50220 supports JIS X 0201-Katakana
* CP50220 supports characters extended by Windows Codepage 932
+ (NEC special characters and NEC selection of IBM extensions)
* Unicode mapping of some characters are different
----------
Charset name: CP50220
Charset aliases: csCP50220
Suitability for use in MIME text:
Yes, CP50220 is suitable for use with subtypes of the "text" Content-Type.
Since the "CP50220" is 7bit encoding, Content-Transfer-Encoding is not needed.
Based64 or Quoted-Printable encoding MAY break this encoding.
Published specification(s):
CP50220 is consisted by following character sets:
reg# character set ESC sequence designated to
------------------------------------------------------
6 US-ASCII ESC ( B G0
13 JIS X 0201-Katakana ESC ( I G0
14 JIS X 0201-Roman ESC ( J G0
42 JIS X 0208-1978 ESC $ @ G0
87 JIS X 0208-1983 ESC $ B G0
* The beggining of a text is assumed to have "ESC ( B ESC ) I".
* Each line of CP50220 text MUST end with ASCII.
* On receiving JIS X 0201-Katakana characters MAY be encoded
with the escape sequence: ESC ( I.
* On sending JIS X 0201-Katakana, it MUST be converted to related
character of JIS X 0208.
* The character set of CP50220 is based on Windows Codepage 932.
So a meaning and a map to Unicode of each character is refer to it.
http://msdn.microsoft.com/en-us/goglobal/cc305152.aspx
ISO 10646 equivalency table:
This charset is ISO/IEC 2022 family.
Conversion of each character refers Windows Codepage 932:
http://msdn.microsoft.com/en-us/goglobal/cc305152.aspx
http://unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WINDOWS/CP932.TXT
http://icu-project.org/repos/icu/data/trunk/charset/data/ucm/windows-932-2000.ucm
Additional information:
This is a request for a new registration of this charset.
CP50220 is a variant of ISO-2022-JP (like Windows-31J and Shift_JIS).
this charset is different from ISO-2022-JP in:
* CP50220 supports JIS X 0201-Katakana
* CP50220 supports characters extended by Windows Codepage 932
(NEC special characters and NEC selection of IBM extensions)
* Unicode mapping of some characters are different
Typical user of CP50220 is web browsers. When web browsers load
a page which are declared or auto-detected as "ISO-2022-JP", they
don't interpret it as true ISO-2022-JP registerd in IANA Character
Sets but as CP50220. When they post form data as "ISO-2022-JP",
the data is also encoded as CP50220. Note that though csISO2022JP
is alias of ISO-2022-JP in IANA Character Sets, on Windows it means
neither registered ISO-2022-JP nor CP50220 but means CP50221.
The name "CP50220" is in use following applications:
* Citrus iconv (NetBSD and DragonFly uses this)
* Mojikan http://www.mirai-ii.co.jp/moji/mojikan/
* nkf 2.0.5
* Encode-EUCJPMS-0.06
Moreover applications which uses MLang.DLL or .NET Framework for
converting "ISO-2022-JP" implicitly uses this charset.
So this charset is widely used, but doesn't have its own name.
Why the name is not "Windows-50220" is some of applications which accept
the name "CP50220" don't support the name "Windows-50220".
CP50220 is for use of communicating with legacy system.
UTF-8 is preferred to CP50220 for new system.
Related references are:
"Remarks" of "GetEncodings Method" of "System.Text"
http://msdn.microsoft.com/en-us/library/system.text.encoding.getencodings.aspx
"UnicodeによるJIS X0213実装入門―情報システムの新たな日本語処理環境"
日経BPソフトプレス, ISBN 978-4891006082, 2008, p. 17-18, 20, 120-158
CP50220 - Legacy Encoding Project
http://legacy-encoding.sourceforge.jp/wiki/index.php?cp50220
This charset is also known as Windows Codepage 50220.
Person & email address to contact for further information:
NARUSE, Yui
Email: naruse@ruby-lang.org
Intended usage: LIMITED USE
--
NARUSE, Yui
naruse@airemix.jp