Editing Double-byte character set (section)

==In CJK computing==
The term ''DBCS'' traditionally refers to a character encoding where each graphic character is encoded in two bytes.

In an 8-bit code, such as [[Big-5]] or [[Shift JIS]], a character from the DBCS is represented with a lead (first) byte with the [[most significant bit]] set (i.e., being greater than seven bits), and paired up with a single-byte character-set (SBCS). For the practical reason of maintaining compatibility with unmodified, off-the-shelf software, the SBCS is associated with [[half-width character]]s and the DBCS with [[full-width character]]s. In a 7-bit code such as [[ISO-2022-JP]], [[ANSI escape sequence|escape sequences]] or [[Shift Out|shift codes]] are used to switch between the SBCS and DBCS.

Sometimes, the use of the term "DBCS" can imply an underlying structure that does not comply with [[ISO 2022]]. For example, "DBCS" can sometimes mean a double-byte encoding that is specifically not [[Extended Unix Code]] (EUC).

This original meaning of DBCS is different from what some consider correct usage today. Some insist that these character encodings be properly called [[multi-byte character set]]s (MBCS) or [[variable-width encoding]]s, because character encodings such as [[EUC-JP]], [[EUC-KR]], [[EUC-TW]], [[GB 18030]], and [[UTF-8]] use more than two bytes for some characters, and they support one byte for other characters.