CJK can also stand for Centre Jeunes Kamenge .

CJK is a collective term for Chinese, Japanese, and Korean, which comprise the largest of East Asian languages. The term is used in the field of software and communications internationalization.

The term CJKV is used to mean CJK plus Vietnamese, which used Chinese characters prior to adopting a written language solely on Romanization.

These languages all share the fact that their writing systems are based partly or entirely on Chinese characters — Hanzi in Chinese, Kanji in Japanese, and Hanja in Korean. Chinese requires between 4000 characters for a basic vocabulary to 40,000 characters for reasonably complete coverage. Whereas Japanese and Korean use fewer characters — complete literacy in Japan can be expected with 2000 characters — idiosyncratic use of Chinese characters in proper names requires many more. This number of characters cannot fit in the 256-character code space of 8-bit encodings, and therefore requires at least a 16-bit fixed width character encoding or multi-byte variable-length encodings. 16-bit fixed width encodings, such as Unicode up to and including version 2.0, are now deprecated due to the requirement that software in China support the GB18030 character set.

Although CJK encodings have common character sets, the encodings often used to represent them have been developed separately by different East Asian governments and software companies, and are mutually incompatible. Unicode has attempted, with some controversy, to unify the character sets in a process known as Han unification.

CJK character encodings should consist minimally of Han characters plus language-specific phonetic scripts such as pinyin, bopomofo, hiragana, katakana, and Hangul.

CJK character encodings include:

• Big5
• EUC-JP
• EUC-KR
• GB18030 (the mandated standard in the People's Republic of China)
• GB2312
• ISO 2022-JP
• Shift-JIS
• Unicode

The CJK character sets take up the bulk of the Unicode code space. There is much controversy among Japanese experts of Chinese characters about the desirability and technical merit of the "Han unification" process used to map multiple Chinese and Japanese characters sets into a single set of unified glyphs.

See also

• Chinese character encoding
• Chinese input methods for computers
• Japanese language and computers
• Korean language and computers
• Variable-width encoding
• Complex Text Layout languages (CTL)

References

• DeFrancis, John. The Chinese Language: Fact and Fantasy. Honolulu: University of Hawaii Press, 1990. ISBN 0824810686.
• Hannas, William C. Asia's Orthographic Dilemma. Honolulu: University of Hawaii Press, 1997. ISBN 082481892X (paperback); ISBN 0824818423 (hardcover).
• Lunde, Ken. CJKV Information Processing. Sebastopol, Calif.: O'Reilly & Associates, 1998. ISBN 1565922247.

External links

• http://www.praxagora.com/lunde/cjk_inf.html