8859

ISO/IEC 8859, commonly referred to as 8859, is a family of eight-bit single-byte character encodings defined by the ISO/IEC 8859 standard. Each part encodes 128 additional characters beyond ASCII, intended to cover specific language groups. In each part, the first 128 code points (0x00–0x7F) preserve ASCII, while the upper half (0xA0–0xFF) contains letters, punctuation, and symbols chosen for the target languages. The 0x80–0x9F range, when defined, generally holds C1 control codes, though some implementations repurpose these bytes (notably in Windows-1252).

The best-known part is ISO/IEC 8859-1, Latin-1, which covers Western European languages. Other parts include ISO/IEC 8859-5 (Cyrillic), ISO/IEC 8859-6 (Arabic), ISO/IEC 8859-7 (Greek), ISO/IEC 8859-8 (Hebrew), and ISO/IEC 8859-9 (Turkish). A later addition, ISO/IEC 8859-15, known as Latin-9, added the euro sign and updated several characters to align more closely with Western European usage; several other parts exist for various languages but saw limited adoption.

Usage and status: these encodings were widely used for web pages, email, and software localization in the 1990s and early 2000s. With Unicode and UTF-8, their use declined, but they persist in some legacy data and systems. They can be mapped to Unicode code points, enabling transcoding, but the mappings are specific to the particular ISO 8859 part. A common pitfall is confusion with Windows-1252, which often fills the 0x80–0x9F range in Western software, making 8859-1 and Windows-1252 visually similar but not identical in some positions.