เครื่องหมายกำกับเสียงแบบรวมสำหรับสัญลักษณ์

Combining Diacritical Marks for Symbols is a Unicode block containing ลูกศร  2190–21FF , dots, enclosures, and overlays for modifying symbol characters.

Talking about linguistics, how can we characterize the diacritical marks? Basically, those are various subscript and superscript symbols, which are applied in letter-alphabets (including consonant-alphabets, like abugidas) and syllable alphabets. Their main feature is that they act not as separate and independent symbols, but as additional marks for changing or narrowing the meaning of a particular sound or letter. Sometimes diacritics are supposed to be smaller than the letter itself.

Synonymous names: accents (more specific), diacritics (professional discourse). Needless to say, a system of diacritics that refers to some script or text is also called a diacritic.

Sometimes one letter may have more than two diacritics at the same time. Just like in the following examples: ặ, ṩ, ᶑ.

The vocal symbols in alphabets like Hebrew, Arabic, and Syriac can be often confused with diacritics due to their similar appearance. However, they mostly act as a special type of letters, so they carry different functions.

When do we use diacritics? Diacritics come in handy if the letters in an alphabet are not enough to express some sounds or meanings. The main alternatives for diacritics are various combinations of two letters (digraphs), three letters or more that convey one sound. For instance, the sound /sh/ is a digraph in English as it is in French /ch/, whereas in German it will be a trigraph /sch/. Are there languages that convey this sound with one letter? Yes, sure, it's clearly reflected in Czech /š/. Plus, in this case we're dealing with a diacritic, which plays the role of this pronunciation facilitator.

Diacritics are used both with consonant and vowel letters. The key drawback of diacritics is that they fill the writing with tiny little details, which are extremely important, and if you forget or skip one, it can lead to serious mistakes and consequences. However, we know a lot of languages which don't use diacritics at all (English) or just a little (Russian). In some cases there's a tendency of replacing diacritical letters with digraphs. The German sound /ö/ becomes /ое/ in the textual versions, but since the introduction of umlaut, this phenomenon is almost out of use.