TC 304 This standard specifies a structure for 7-bit and 8-bit codes that is adopted by all such codes produced under the auspices of ISO/IEC JTC1/SC2. This is the subcommittee entrusted jointly by ISO and IEC with the development of character set coding matters.
This standard also specifies means by which the correspondence between bit combinations and characters may be changed during a particular instance of information interchange. This is known as code extension. It makes use of control functions that are themselves represented by bit combinations within the original code.
This guide contains introductions to the features of ISO/IEC 2022 at various levels: