Code page 932 (abbreviated as CP932, also known by the IANA name Windows-31J) is Microsoft's extension of Shift JIS to include NEC special characters (Row 13), NEC selection of IBM extensions (Rows 89 to 92), and IBM extensions (Rows 115 to 119). The coded character sets are JIS X0201:1997, JIS X0208:1997, and these extensions. Windows-31J is often mistaken for Shift JIS: while similar, the distinction is significant for computer programmers wishing to avoid mojibake, and a good reason to use the world-widely unambiguous UTF-8 instead. The windows-31J name, however, is IANA's and not recognized by Microsoft, which historically has used shift_jis instead.
In Japanese editions of Windows, this code page is referred to as "ANSI", since it is the operating system's default 8-bit encoding, even though ANSI was not involved in its definition.
Code page 932 contains standard 7-bit ASCII codes, and Japanese characters are indicated by the high bit set to 1. Some code points in this page require a second byte, so characters use either 8 or 16 bits for encoding.