(1) The underlying part of a code page that defines: a) the coding space (the number and allowable value of code points in a code page); b) the rules for sharing the coding space between control and graphic characters; and c) the rules related to the specific options permitted in that scheme, such as the number of bits in a byte, single-byte, or double-byte.
(2) The set of rules that specifies the values for control characters and graphic characters. Examples of encoding schemes include ASCII, ISO/IEC 10646, Unicode and IBM's EBCDIC.
(3) A set of rules to represent character data.