dediacritization

Dediacritization, also known as dediacritization, is the process of removing diacritical marks from letters in a text to produce a form that uses base letters without diacritics. Diacritics include marks such as acute, grave, circumflex, tilde, diaeresis, caron, cedilla, and similar symbols that indicate pronunciation, tone, or distinctions in meaning in many writing systems. Dediacritization thus transforms a written form while attempting to preserve the underlying letters as far as possible.

The methods used range from simple, rule-based mappings to more sophisticated language-aware approaches. A common technique is to replace each accented character with its unaccented counterpart (for example, é → e). More complex implementations may consider language-specific distinctions to minimize resulting ambiguity or prevent misinterpretation, and in some historical or transliteration tasks, diacritics may be converted to multi-letter sequences. In computational pipelines, the process often involves Unicode normalization followed by the selective removal of combining diacritic marks, with attention to cases where a diacritic encodes a distinct letter rather than mere pronunciation.

Applications of dediacritization include text normalization for search and indexing, cross-language data exchange, and preprocessing for OCR, machine translation, and spell-checking. It can facilitate comparisons across scripts and improve compatibility with systems that restrict characters to a limited ASCII set. However, the procedure inherently risks loss of information and potential meaning changes, since many diacritics encode phonemic distinctions or lexical differences that are not recoverable from base letters alone. Language-aware approaches can mitigate some issues but cannot guarantee reversible or unambiguous results in all contexts.