Nondiacritic

Nondiacritic refers to a character that lacks diacritical marks. In typography, diacritics are marks added to letters to indicate modification of sound, pronunciation, tone, or other linguistic features. The nondiacritic form is the unmarked base letter, and it is often used in contexts where diacritics are not supported or are deliberately omitted, such as ASCII-only text or search indexing.

In Unicode and text processing, stripping diacritics to obtain a nondiacritic form involves removing combining diacritical marks from decomposed characters. For example, é can be represented as e plus an acute accent; removing the accent yields the nondiacritic letter e. Similarly, ö becomes o with diaeresis, which reduces to o in a nondiacritic form. Some letters exist as distinct nondiacritic characters; however, many languages rely on diacritics to distinguish words, and removing them can alter meaning or pronunciation.

Applications include linguistic research, typography, optical character recognition, and information retrieval, where nondiacritic forms can improve search robustness across languages. However, in multilingual contexts, the nondiacritic form may obscure orthographic distinctions and should be used with care. In transliteration and data interchange, nondiacritic forms are common for compatibility with ASCII or systems that do not support diacritics, as in cafe, resume, facade instead of café, résumé, façade.

See also: diacritic, Unicode, ASCII, Unicode normalization.