Because of vowel harmony, all vowels in a word are affected, so the scope of the diacritic is the entire word.
In abugida scripts, like those used to write Hindi and Thai, diacritics indicate vowels, and may occur above, below, before, after, or around the consonant letter they modify.
were developed with a bias favoring English, a language with an alphabet without diacritical marks.
This has led to fears internationally that the marks and accents may be made obsolete to facilitate the worldwide exchange of data.
In orthography and collation, a letter modified by a diacritic may be treated either as a new, distinct letter or as a letter–diacritic combination.
This varies from language to language, and may vary from case to case within a language.
Vowel pointing systems, namely the Arabic harakat ( ), which, respectively, mark abbreviations or acronyms, and Greek diacritical marks, which showed that letters of the alphabet were being used as numerals.
In the Hanyu Pinyin official romanization system for Chinese, diacritics are used to mark the tones of the syllables in which the marked vowels occur.
The tittle (dot) on the letter i of the Latin alphabet originated as a diacritic to clearly distinguish i from the minims (downstrokes) of adjacent letters.
It first appeared in the 11th century in the sequence ii (as in ingeníí), then spread to i adjacent to m, n, u, and finally to all lowercase i's.
With the advent of Roman type it was reduced to the round dot we have today.
Different languages use different rules to put diacritic characters in alphabetical order.
For a comprehensive list of the collating orders in various languages, see Collating sequence.