ASCII

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Stands for: American Standard Code for Information Interchange

The 7-bit character code that numbers 0 to 127 the English letters, the digits, punctuation and 33 control codes; the first 128 code points of Unicode.

Its 128 codes sit under almost everything a network engineer reads: HTTP headers, SMTP commands, host names in their ASCII form, configuration files. Seven bits leave no room for accented letters, which is why so many 8-bit charsets were built on top of it, and it survives inside UTF-8 byte for byte. RFC 20 (1969) reproduces the 1968 version of the standard, then called the USA Standard Code for Information Interchange. A browser told a page is in "ascii" reads windows-1252 instead.

Also known as: us-ascii, usascii, usas x3.4-1968

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