ISO88591like

ISO88591like is an informal designation used in software documentation to describe a class of character encodings that are Latin-1–like. It is not an official encoding name. In practice, encodings labeled as ISO88591like are expected to map the byte range 0x00–0xFF to the first 256 Unicode code points, with the ASCII range matching ASCII and the upper half representing Latin-1–style characters. However, because the term is informal, exact mappings can vary, so a concrete mapping should be consulted.

The relationship to ISO/IEC 8859‑1 varies. ISO-8859-1 defines a specific mapping for the 0xA0–0xFF block. Some encodings described as ISO88591like may align with ISO-8859-1, while others resemble Windows-1252 or ISO-8859-15 in part, especially in the 0x80–0x9F range or with additional characters such as the euro sign. Windows-1252 is commonly described as Latin‑1–like but is not identical to ISO-8859-1.

In practice, ISO88591like serves as a heuristic label in documentation or code, signaling that byte values are intended to map directly to the basic Latin and Western European characters. For precise data interchange, developers should rely on explicit encodings such as ISO/IEC 8859‑1 or UTF-8 and consult the exact mapping table of the implementation.