ISO-IR-165 explained

CCITT Chinese set (ISO-IR 165)
Mime:iso-ir-165
Alias: (EUC form)
Definitions:ISO-IR 165
Standard:ITU T.101, annex C
Lang:Simplified Chinese, English, Russian
Partial support:
Greek, Japanese
Extends:GB 2312
Next:GB 18030
Encodings:ISO-2022-CN-EXT, Videotex Data Syntax 2

The CCITT Chinese Primary Set is a multi-byte graphic character set for Chinese communications created for the Consultative Committee on International Telephone and Telegraph (CCITT) in 1992.[1] It is defined in ITU T.101, annex C, which codifies Data Syntax 2 Videotex.[2] It is registered with the ISO-IR registry for use with ISO/IEC 2022 as ISO-IR-165, and encodable in the ISO-2022-CN-EXT code version.

It is an extended modification of GB/T 2312-80, and corresponds to the union of the mainland Chinese GB standards GB 6345.1-86 and GB 8565.2-88, with some further modification and extensions. A subset of the GB 6345.1 extensions are incorporated into GB 18030, while GB 8565.2 serves as the mainland Chinese source reference for certain CJK Unified Ideographs.

GB 6345.1

GB 6345.1-86 (32 × 32 Dot Matrix Font Set of Chinese Ideographs for Information Interchange) includes both a corrigendum and an extension for GB 2312. The corrigendum alters the following two characters:

Row-cell!!EUC!!GB 2312 (Unamended)[3] !!GB 6345.1!!Notes
03-710xA3E7ɡ
79-810xEFF1

Deployed implementations incorporating GB 2312, such as Windows code page 936, generally follow these corrections in mapping 79-81 to U+953A.[4]

The extension adds half-width ISO 646-CN characters in row 10 (in addition to the existing full-width characters in row 3) and extends the set of 26 non-ASCII pinyin characters in row 8 with six additional such characters. These GB 6345.1 extensions are also incorporated into GB/T 12345, the Traditional Chinese counterpart to GB 2312, in addition to 29 vertical presentation forms in row 6.[5]

Later GB/T 6345.1-2010 published in 2011 officially adds half-width forms of the 32 pinyin characters (including the six new additions) in row 8 to row 11.[6] This addition is not featured in GB 18030.

The six additional pinyin characters from GB 6345.1 and the vertical presentation forms from GB 12345 — but not the half-width forms — are included in the classic Mac OS encoding for Simplified Chinese (a modification of EUC-CN), and also as two-byte codes in GB 18030.[7] The additional pinyin characters are as follows:[8]

Row-cell!!EUC!!Character!!Notes
08-270xA8BB
08-280xA8BC
08-290xA8BD
08-300xA8BE
08-310xA8BF
08-320xA8C0
These extensions and modifications to GB 2312 were first introduced in GB 5007.1-85 in 1985.

GB 8565.2

GB 8565.2-88 (Information Processing - Coded Character Sets for Text Communication - Part 2: Graphic Characters) defines an extension for GB 2312, adding 705 characters between rows 13–15 and 90–94, of which 69 (all in row 15) are non-hanzi. It includes the GB 2312 corrections from GB 6345.1, but not its extensions.

The Unihan database references GB 8565.2 as the mainland Chinese source of several hanzi included in Unicode. Its Unihan source abbreviation is .

CCITT changes

ISO-IR-165 incorporates the GB 2312 extensions from both GB 6345.1-86 and GB 8565.2-88. Additionally, it adds 161 further characters (including 139 hanzi, identified as “general Chinese characters and variants”).[9] These CCITT hanzi extensions have on occasion been mistaken for standard GB 8565.2 characters, including in previous revisions of the Unihan database. In total the set contains 8446 characters.

A number of patterned semigraphic characters are included in row 6.[9] This collides with the vertical presentation forms included in other extensions such as Mac OS Simplified Chinese[8] and GB 18030.[7]

The GB 6345.1 corrections to GB 2312 are applied, but two Unicode mappings are reversed compared to other encodings which include GB 2312 with GB 6345.1 extensions. The table below shows the mappings and their corresponding glyphs including GB 18030:

Row-cellEUCGB 2312 (unamended)GB 6345.1GB 6345.1 mappingISO-IR-165ISO-IR-165 mapping[10] GB 18030GB 18030 mapping
03-710xA3E7ɡɡ
08-320xA8C0(absent)ɡ
79-810xEFF1

References

  1. Book: Lunde , Ken . Ken Lunde

    . CJKV Information Processing: Chinese, Japanese, Korean & Vietnamese Computing . Ken Lunde . 2009 . 2nd . . . 978-0-596-51447-1 . 94–111 .

  2. Web site: Pseudo-G8 characters . Chung . Jaemin . 2018-01-24 . ISO/IEC JTC 1/SC 2/WG 2/IRG N2276.
  3. 58 . Coded Chinese Graphic Character Set for Information Interchange . China Association for Standardization.
  4. Web site: cp936 to Unicode table . 2000 . Steele . Shawn . Microsoft, Unicode Consortium.
  5. Book: Lunde, Ken . Appendix F: GB/T 12345 . Ken Lunde . CJKV Information Processing . 9781565922242 . 1998 . O'Reilly Media.
  6. Book: Standardization Administration of China (SAC) . GB/T 6345.1-2010 信息技术 汉字编码字符集(基本集) 32点阵字型 第1部分宋体 . 2011-01-10 . China . zh-CN.
  7. Book: Standardization Administration of China (SAC). GB 18030-2005: Information Technology—Chinese coded character set. 2005-11-18.
  8. Web site: Map (external version) from Mac OS Chinese Simplified encoding to Unicode 3.0 and later.. Apple, Inc.
  9. 165 . Codes of the Chinese graphic character set for communication . 1992-07-13 . CCITT . ITU-T.
  10. Web site: Unicode to ISO-IR-165 table . Raghuram . Viswanadha . 2000-08-30 . . International Components for Unicode. (Note: codes are listed in the source in 7-bit form: add 0x80 to each byte for EUC form, or subtract 0x20 for kuten form)

External links