diacritical

Diacritical is an adjective relating to diacritics. A diacritic is a mark added to a letter to modify its sound, stress, tone, or meaning. Diacritical usage encompasses marks placed above, below, or through letters in many writing systems. The term is also used to describe the system of such markings.

Etymology: The word derives from Latin diacriticus, from Greek diakritikos, from dia- "through" and kritikos "able to discern." The concept covers a wide variety of signs, from the acute accent to the dot or tilde.

Common marks include the acute (á) and grave (à) accents, which indicate vowel quality or stress in languages like Spanish and French; the circumflex (â, ê); the tilde (ñ, ã); diaeresis/umlaut (ä, ö); the cedilla (ç); caron/hacek (č, š); the ring (å); macron (ā) and breve (ă); dot above (i, j); and ogonek (ą). Diacritics are essential in many languages for pronunciation and meaning; examples span Spanish, French, Portuguese, Polish, Turkish, and many others.

Technology and typography: In Unicode, diacritics may be encoded as precomposed characters (é) or as a base letter plus combining marks (e + ́). Unicode normalization (NFC, NFD) affects equivalence of these representations. In computing, diacritics influence search, sorting, and transliteration, and their handling varies across systems.

Usage: Some languages rely on diacritics to distinguish otherwise identical words; in transliteration or URLs, diacritics are sometimes omitted or replaced, which can alter meaning or readability. Preserving diacritics is generally important for accuracy and cultural integrity.