ISO/IEC 646
international standard for 7-bit character encoding, adapted to several simplified Latin alphabets
ISO/IEC 646, is an ISO/IEC standard in the field of character encoding. It is equivalent to the ECMA standard ECMA-6 and developed in cooperation with ASCII at least since 1964. The first version of ECMA-6 had been published in 1965, based on work the ECMA's Technical Committee TC1 had carried out since December 1960. The first edition of ISO/IEC 646 was published in 1973, and the most recent, third, edition in 1991.
ISO/IEC 646 specifies a 7-bit character code from which several national standards are derived. It allocates a set of 82 unique graphic characters to 7-bit code points, known as the invariant (INV) or basic character set, including letters of the ISO basic Latin alphabet, digits, and some common English punctuation. It leaves 12 code points to be allocated by conforming national standards for additional letters of Latin-based alphabets or other symbols.
It also defines the International Reference Version (IRV), including a full allocation of 94 graphic characters, to be used when a specific national version is not required. As of the 1991 edition of ISO/IEC 646, the IRV and ASCII are identical. Previous editions differed in only one or two code points.
“ISO/IEC 646” enters the record as international standard for 7-bit character encoding, adapted to several simplified Latin alphabets. Crown Archives preserves that source wording while asking what international, standard and 7-bit can confirm, complicate or overturn.
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“ISO/IEC 646” is worth following because a concise public description often conceals a longer documentary argument. Here, international, standard and 7-bit provides the most credible route into that argument.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 25, 2026. The linked authority identifier is Q764925. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1964, 1965, 1960 and 1973.
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This entry incorporates text from “ISO/IEC 646” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.