In 1990 the Japanese Standards Association (JSA) released a supplementary character set standard: JIS X 0212-1990 Code of the Supplementary Japanese Graphic Character Set for Information Interchange (情報交換用漢字符号-補助漢字, Jōhō Kōkan'yō Kanji Fugō - Hojo Kanji). This standard was intended to build upon the range of characters available in the main JIS X 0208 character set, and to address shortcomings in the coverage of that set.
Features
The standard specified 6,067 characters, comprising:
No encapsulation of JIS X 0212 characters in the popular Shift JIS encoding is possible, as Shift JIS does not have sufficient unallocated code space for the characters.
Implementations
Encoding of JIS X 0212 in conformant EUC-JP (left) and Windows code page 20932 (right).
JIS X 0212 is called Code page 953 by IBM, which includes vendor extensions.[2][3][4] The alternative CCSID5049 excludes these extensions.[5]
As JIS X 0212 characters cannot be encoded in Shift JIS, the coding system which has traditionally dominated Japanese information processing, few practical implementations of the character set have taken place. As mentioned above, it can be encoded in EUC-JP, which is commonly used in Unix/Linux systems, and it is here that most implementations have occurred:
in the early 1990s basic "BDF" fonts were compiled for use in the Unix X Window System;
an IME conversion file was compiled for the Wnn system;
the kterm console window application was extended to support it;
the Emacs and jstevie editors were extended to support it.
the WWWJDIC Japanese dictionary server (however as Internet Explorer does not support the JIS X 0212 extensions in EUC, this server sends bitmapped graphics for these characters when set in EUC-JP mode.)
JIS X 0212 and Unicode
The kanji in JIS X 0212 were taken as one of the sources for the Han unification which led to the unified set of CJK characters in the initial ISO 10646/Unicode standard. All the 5,801 kanji were incorporated.
The future
Apart from the applications mentioned above, the JIS X 0212 standard is effectively dead. 2,743 kanji from it were included in the later JIS X 0213 standard. In the longer term, its contribution will probably be seen to be the 5,801 kanji which were incorporated in Unicode.