Important character sets include:
- ISO 646, an ASCII subset with certain positions reserved for local characters. ISO 646 is one of the main reasons C has those icky trigraphs.
- ASCII (ISO 646-IRV).
- Latin-1 (ISO 8859-1), the most widely-used 8-bit western-European character set until Unicode and Latin-9
- Latin-9 (ISO 8859-15), based on Latin-1, but adding capital and lowercase s-caron, z-caron, the Euro symbol, the French oe ligature (capital and lowercase), and capital Y-diaeresis.
- the other character sets in the ISO 8859 family.
- VISCII (Vietnamese Standard Code for Information Interchange); now part of RFC 1456.
- KOI8-R, a Cyrillic character set described in RFC 1489; also known as CP878. Based on KOI8, which also spawned KOI8-U and other character sets.
- CP437 (DOSLatinUS), the standard DOS character set.
- CP850 (DOSLatin1), which contained the characters from Latin1, but in different positions, so that the CP437 line-drawing characters would still be in the same place.
- CP1252 (WinLatin1), the default Windows character set; a superset of Latin-1.
- EBCDIC (Extended Binary Coded Decimal Information Code), common on IBM mainframes.
- Unicode (ISO 10646 or UCS), which aims to represent the characters of every language; there are a number of different encodings, the most common of which are UTF-8, UTF-16/UCS-2 (defined by different standards but more or less compatible), and UCS-4.