Editing Combining character (section)

{{short description|Non-spacing character that modifies another character}}
{{Distinguish|Spacing Modifier Letters}}
[[File:U nieskładovaje Unicode.svg|thumb|[[U (Cyrillic)|Cyrillic U]] combined with [[breve]] gives [[Short U (Cyrillic)|ў]].]]
{{Contains special characters}}

In [[digital typography]], '''combining characters''' are [[Character (computing)|characters]] that are intended to modify other characters. The most common combining characters in the Latin script are the '''combining [[diacritic|diacritical marks]]''' (including '''combining accents'''). 

[[Unicode]] also contains many [[precomposed character]]s, so that in many cases it is possible to use both combining diacritics and precomposed characters, at the user's or application's choice. This leads to a requirement to perform [[Unicode normalization]] before comparing two Unicode strings and to carefully design encoding converters to correctly map all of the valid ways to represent a character in Unicode to a legacy encoding to avoid data loss.<ref>For example, when converting between [[windows-1258]] and [[VISCII]], the former uses combining diacritics whilst the latter has a large selection of precomposed characters so a converter using a simple mapping between code values and Unicode code points will corrupt text when converting between them.</ref>

In Unicode, the main block of combining diacritics for European languages and the [[International Phonetic Alphabet]] is U+0300–U+036F. Combining diacritical marks are also present in many other blocks of Unicode characters. In Unicode, diacritics are always added after the main character (in contrast to some older combining character sets such as [[ANSEL]]), and it is possible to add several diacritics to the same character, including stacked diacritics above and below, though some systems may not render these well.