Western Latin character sets

Summary

• ISO/IEC 8859-1 or Latin-1 is the most used and also defines the first 256 codepoints in Unicode.
• ISO/IEC 8859-15 modifies ISO-8859-1 to fully support Estonian, Finnish and French and add the euro sign.
• Windows-1252 is a superset of ISO-8859-1 that includes the printable characters from ISO/IEC 8859-15 and popular punctuation such as curved quotation marks. It is common that web page tools for Windows use Windows-1252 but label the web page as using ISO-8859-1, this has been addressed in HTML5, which mandates that pages labeled as ISO-8859-1 must be interpreted as Windows-1252.
• IBM CP437, being intended for English only, has very little in the way of accented letters but has far more graphics characters than the other IBM code pages listed here and also some mathematical and Greek characters that are useful as technical symbols.
• IBM CP850 has all the printable characters that ISO-8859-1 has and still manages to have enough graphics characters to build a usable text-mode user interface.
• IBM CP858 differs from CP850 only by one character — a dotless i, rarely used outside Turkey and with no uppercase equivalent provided, was replaced by euro currency sign.
• IBM CP859 contains all the printable characters that ISO/IEC 8859-15 has, so unlike CP850 it supports the euro sign, Estonian, Finnish and French.
• IBM code pages 037, 500, and 1047 are EBCDIC encodings that include all of the ISO-8859-1 characters.
• The Mac OS Roman character set has most, but not all, of the same characters as ISO/IEC 8859-1 but in a very different arrangement; and it also adds many technical and mathematical characters and more diacritics. Older Macintosh web browsers were known to munge the few characters that were in ISO/IEC 8859-1 but not their native Macintosh character set when editing text from Web sites. Conversely, in Web material prepared on an older Macintosh, many characters were displayed incorrectly when read by other operating systems. The Latin encoding">Latin script">Latin encoding, a modification of Mac OS Roman to support ISO/IEC 8859-1, was created by the creators of Kermit (protocol) to solve this problem.

History

The euro sign

• Apple with MacRoman and Sun Microsystems with Solaris OS simply replaced the generic currency sign. This caused difficulty in some places because organisations had found other uses for its code point, such as the company logo.
• ISO introduced a further variant of ISO 8859, ISO 8859-15, which replaced the generic currency sign with the euro sign as well as making some other replacements of symbols with letters with diacritics. ISO 8859-15 never received widespread adoption.
• With Windows-1252, Microsoft placed the euro sign in a gap in the existing C1 control codes, a decision that other vendors considered counter-architectural.

Comparison table

• The mappings for the IBM code pages are from the Unicode site supplied by Microsoft. The Unicode Consortium's document has links to sources giving the differences between IBM's and Microsoft's mappings for these code pages.
• IBM437 and IBM850 defined printable characters for the control code ranges. While these could not be used when printing text through DOS, as they would be trapped before reaching the screen, they could be used by applications that used screen memory directly.
• Macintosh has an Apple logo at 0xF0, and translates it to U+F8FF in the Private Use Area for Unicode.