EUC

EUC is one of the main character coding methods for East Asian languages. It was developed by AT&T for System V UNIX. Nowadays, it's mostly used for Japanese and Korean, although ISO-2022 and Unicode have become more common standards for both languages since then.

For Japanese, EUC codes are derived by shifting the first and third digit of the four-digit JIS X 0208 code (in hexadecimal) up by eight. So the character 亜, which has a JIS code of 3021, would be B0A1 in EUC encoding.

EUC is an 8-bit encoding, which means that some older e-mail and newsgroup systems will mess up the characters. JIS, which is 7-bit, is still usually recommended for Japanese e-mail; EUC has become a more acceptable standard for web pages and the like.

Type    Language      Codeset 0    Codeset 1        Codeset 2        Codeset 3
EUC-C   Chinese (PRC) ASCII        GB 2312-1980     undefined        undefined
EUC-JP  Japanese      ASCII        JIS X 0208-1990  half-width kana  undefined
EUC-KR  Korean        ASCII        KS C 5601-1987   undefined        undefined
EUC-TW  Chinese (ROC) ASCII        CNS 11643-1986   CNS 11643-1986   undefined