C0 and C1 control codes

The C0 and C1 control code sets define control codes for use in text. C0, originally defined in ISO 646, defines codes in the range 00HEX–1FHEX. C1, originally defined in ISO 6429, defines codes in the range 80HEX–9FHEX. The C0 codes are contained in ASCII and most encodings based on it. The C1 codes were included in the ISO-8859-n series of encodings and Unicode but are rarely used. When they turn up in documents, Web pages, e-mail messages, etc., which are ostensibly in an ISO-8859-n encoding, their code positions were reused to refer to the characters at that position in a proprietary, system-specific encoding such as Windows-1252 or the Apple Macintosh ("MacRoman") character set.
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