Character encoding

Character Encodings are methods of representing characters of text, usually as numeric values which can be stored on computers as bits and bytes, but sometimes in other things (e.g., Braille represents them as patterns of raised dots). Sometimes they're also referred to as "character sets", but purists will make a distinction in that, strictly speaking, a character set is merely a repertoire of characters, the list of characters supported by some system, protocol, or file format, without it necessarily having any inherent order or numbering system. A character encoding assigns specific values (in some coding system) to each character. However, the distinction can get vague and fuzzy; there are multiple levels of abstraction (Unicode includes a set of defined characters as well as assigned numeric code points for each, but leaves it to other more specific encodings such as UTF-8 to define the specific bits/bytes that represent them in a file), and some protocols even use parameter names such as 'charset' to indicate which character encoding is in use, so the terminology can slip and slide even in "tech" uses. This section documents all the various sorts of character sets/encodings of any sort.

See Fonts for the renditions of character encodings as seen on screens and printouts. The appearance of a character is known as a "glyph", and a font consists of a set of glyphs mapped onto the more abstractly-defined characters as included in the character set that is part of a character encoding.

Specific character sets or encodings

 * Adobe Standard Encoding
 * Amstrad CP/M Plus character set
 * ANSEL
 * MARC-8
 * APL code page
 * ARMSCII
 * ASCII
 * ATASCII (used by Atari computers)
 * Baudot code
 * Braille
 * BRF
 * Nemeth Code
 * Taylor Code
 * Compucolor character set
 * DEC (Digital Equipment Corporation)
 * DEC Special Graphics Character Set
 * PDP-1 alphanumeric codes
 * EBCDIC
 * CP037
 * CP285
 * CP424
 * CP500
 * CP875
 * CP1026
 * CP1047
 * CP1140
 * CP1148
 * CP1155
 * CP4971
 * CP9067
 * CP12712
 * EBCDIC 6-Bit
 * Flag semaphore
 * GB 2312
 * IBM: See EBCDIC, MS-DOS Encodings, and APL Code Page elsewhere in this list
 * ISO 646
 * ISO 646-CA (Canada / French)
 * ISO 646-CA-2 (Canada / French)
 * ISO 646-CH (Switzerland)
 * ISO 646-CN (China / Basic Latin)
 * ISO 646-CU (Cuba / Spanish)
 * ISO 646-DE (Germany)
 * ISO 646-DK (Denmark)
 * ISO 646-FI (Finland)
 * ISO 646-FR (France)
 * ISO 646-GB (Great Britain)
 * ISO 646-HU (Hungary)
 * ISO 646-IRV (International Reference Version)
 * ISO 646-IT (Italy)
 * ISO 646-JP (Japan / Romaji)
 * ISO 646-JP OCR-B (Japan / Romaji)
 * ISO 646-KR (Korea / Latin)
 * ISO 646-MT (Malta)
 * ISO 646-NL (Netherlands)
 * ISO 646-NO (Norway)
 * ISO 646-NO-2 (Norway)
 * ISO 646-PT (Portugal)
 * ISO 646-SE (Sweden)
 * ISO 646-SE-2 (Sweden)
 * ISO 646-US (Same as ASCII)
 * ISO 646-YU (Yugoslavia)
 * ISO 2022
 * ISO 8859
 * ISO 8859-1 (Latin-1)
 * ISO 8859-2 (Latin-2, Central/East European)
 * ISO 8859-3 (Latin-3, Esperanto, Galician, Maltese, and Turkish)
 * ISO 8859-4 (Latin-4, Scandinavian and Baltic)
 * ISO 8859-5 (Cyrillic)
 * ISO 8859-6 (Arabic)
 * ISO 8859-7 (Modern Greek)
 * ISO 8859-8 (Hebrew)
 * ISO 8859-9 (Latin-5, Turkish)
 * ISO 8859-10 (Latin-6, Lappish, Nordic, and Inuit)
 * ISO 8859-11 (Thai)
 * ISO 8859-13 (Latin-7, Baltic Rim)
 * ISO 8859-14 (Celtic)
 * ISO 8859-15 (Latin-9, Latin-1 with a Euro sign)
 * ISO 8859-16 (Romanian)
 * JIS
 * JIS X 0201
 * JIS X 0208
 * Shift-JIS
 * KOI8
 * KOI8-CS (Czechoslovakia)
 * KOI8-R (Russia)
 * KOI8-U (Ukraine)
 * Macintosh encodings
 * MacCE
 * MacCyrillic
 * MacDingbat
 * MacGreek
 * MacGujarati
 * MacGurmukhi
 * MacIceland
 * MacRoman
 * MacRomania
 * MacSymbol
 * MacThai
 * MacTurkish
 * MacUkraine
 * Mattel Aquarius character set
 * Morse code
 * MS-DOS encodings (IBM PC code pages)
 * CP437 (Latin US)
 * CP737 (Greek)
 * CP775 (Baltic Rim)
 * CP850 (Latin-1)
 * CP851 (Greek 1)
 * CP852 (Latin-2)
 * CP855 (Cyrillic)
 * CP857 (Turkish)
 * CP860 (Portuguese)
 * CP861 (Icelandic)
 * CP862 (Hebrew)
 * CP863 (French Canada)
 * CP864 (Arabic)
 * CP865 (Nordic)
 * CP866 (Cyrillic CIS 1)
 * CP869 (Greek 2)
 * PETSCII (or PET ASCII or CBM ASCII; used by Commodore computers)
 * Unicode
 * BOCU-1
 * CESU-8
 * GB18030
 * Punycode
 * SCSU
 * UCS-2
 * UTF-1
 * UTF-7
 * UTF-8
 * UTF-9
 * UTF-16
 * UTF-18
 * UTF-32 (UCS-4)
 * UTF-EBCDIC
 * WTF-8
 * VISCII
 * Windows encodings
 * Windows 1252 (ISO 8859-1 plus additional characters)
 * Windows 1255 (Hebrew)
 * Windows 1256 (Arabic, Farsi, Urdu)
 * Windows 1257 (Baltic Rim)
 * Windows 1258 (Vietnamese)
 * ZSCII, used in Infocom games

Format details

 * Byte Order Mark
 * C0 controls (ASCII control characters, 7 bit)
 * C1 controls (extended control characters, 8 bit)

Character encoding naming and numbering systems

 * Code page identifier
 * IANA character set name

Character escape codes
(used to enter characters in various systems and formats) See also ANSI escape code.
 * Alt codes (DOS/Windows)
 * Backslash escapes (used in various programming and markup languages)
 * HTML character references (entities and numeric values)

C++

 * char (C++) at least 8 bits
 * char16_t no less than 16 bits, no less than char
 * char32_t no less than 32 bits, no less than char16_t
 * wchar_t whatever the largest block of addressable memory happens to be on the system

Glib library

 * gunichar Unicode character (variable memory length)

Java Virtual Machine

 * char (Java) exactly 16 bits that represent UCS2
 * java.lang.Character exactly 16 bits that represent UCS2 wrapped in an object

Scala
Both char and scala.Char are wrappers around JVM's original types.

.Net framework

 * System.Char exactly 16 bits that represent UCS2 (This is C#'s char)

QuickBasic
There is no single character datatype. (There's STRING that holds up to 32767 characters assumed to be 1 byte each).

Tools

 * GNU libiconv
 * APR-iconv
 * ICU
 * Recode
 * Kreative Recode: software to convert character encodings

Commentary and satire

 * The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) by Joel Spolsky
 * The Language Double-Take: Dealing with Bidirectional Text (or: Wait, ?tahW)
 * Character encoding bugs are 𝒜wesome!
 * xkcd: Encoding
 * 8 New Punctuation Marks We Desperately Need
 * 8 Symbols We Turned Into Words
 * I Can Text You A Pile of Poo, But I Can’t Write My Name

Other external links

 * Lots of character encoding charts
 * The Evolution of Character Codes, 1874–1968
 * Collection of character encodings