(1) A 7-bit coded character set for information interchange. It is the U.S. national variant of ISO/IEC 646 and is formally the U.S. standard ANSI X3.4. It was proposed by ANSI in 1963 and finalised in 1968. (2) The set of 128 Unicode characters from U+0000 to U+007F, including control codes as well as graphic characters. (3) ASCII has been incorrectly used to refer to various 8-bit character encodings that include ASCII characters in the first 128 code points.