Shift JIS - Multiple Versions

Multiple Versions

Many different versions of Shift JIS exist, conflicting with some code points. This is one reason why applications are recommended to use Unicode such as UTF-8 or UTF-16 instead.

There are two areas for expansion: Firstly, JIS X 0208 does not fill the whole 94×94 space encoded for it in Shift JIS, therefore there is room for more characters here — these are really extensions to JIS X 0208 rather than to Shift JIS itself. The most popular extension here is to the Windows-31J, otherwise known as Code page 932, popularized by Microsoft, although Microsoft itself does not recognize the Windows-31J name and instead calls that variation "shift_jis". Secondly, Shift JIS has more encoding space than is needed, for JIS X 0201 and JIS X 0208 and this space can and is used for yet more characters. The space, with lead bytes 0xF5 to 0xF9, is used by Japanese mobile phone operators for pictographs for use in E-mail, for example. (KDDI goes further and defines hundreds more in the space with lead bytes 0xF3 and 0xF4).

Beyond even this, there have been numerous minor variations made on Shift JIS, with individual characters here and there altered. Most of these extensions and variants have no IANA registration, so there is much scope for confusion, if the extensions are used. Microsoft Code Page 932 is registered separately from Shift JIS.

IBM CCSID 943 has the same extensions as Code Page 932. As with most code pages and encodings, it is recommended by Microsoft, Apple, the Unicode Consortium and most major operating system makers that Unicode be used instead.