ISO88591iin

The term ISO88591iin appears to be a nonstandard spelling or variant of ISO-8859-1, a widely used character encoding in the ISO/IEC 8859 family. The standard name is ISO/IEC 8859-1, and it is commonly known as Latin-1. It is a single-byte character encoding intended to represent Western European languages.

ISO-8859-1 uses eight bits per character, allowing for 256 code points. The first 128 code points (0x00 to 0x7F) coincide with ASCII, ensuring ASCII compatibility. The range 0x80 to 0x9F is defined as C1 control codes, while 0xA0 to 0xFF contains the Latin-1 letters with diacritics, punctuation, and several symbols. This design covers languages such as English, French, German, Spanish, Italian, and Portuguese, including characters like à, é, ñ, ö, and ç.

In practice, ISO-8859-1 was widely used on the early internet, email, and legacy systems. It is not sufficient for languages requiring more diacritics or entirely different scripts, so it does not provide full coverage for Central or Eastern European languages. Some environments treated the 0x80–0x9F range as printable characters due to Windows-1252, which led to confusion between encodings.

Today, Unicode and UTF-8 have largely supplanted ISO-8859-1 for new software because they offer a unified solution for all scripts. ISO-8859-1 remains relevant for historical data and certain legacy systems. For broader Western European coverage, ISO-8859-15 is sometimes used as an updated alternative that includes the euro sign and additional characters.