In other alphabetic systems, diacritical marks may perform other functions.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.Efforts have been made to create internationalized domain names that further extend the English alphabet (e.g., "pokémon.com").Depending on the keyboard layout, which differs amongst countries, it is more or less easy to enter letters with diacritics on computers and typewriters.With the advent of Roman type it was reduced to the round dot we have today.), were used to mark pitch accents in Hangul for Middle Korean.They were written to the left of a syllable in vertical writing and above a syllable in horizontal writing.For a comprehensive list of the collating orders in various languages, see Collating sequence.Modern computer technology was developed mostly in English-speaking countries, so data formats, keyboard layouts, etc.

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.

Examples are the diaereses in the borrowed French words naïve and Noël, which show that the vowel with the diaeresis mark is pronounced separately from the preceding vowel; the acute and grave accents, which can indicate that a final vowel is to be pronounced, as in saké and poetic breathèd; and the cedilla under the "c" in the borrowed French word façade, which shows it is pronounced .

In Gaelic type, a dot over a consonant indicates lenition of the consonant in question.

Other letters modified by diacritics are treated as variants of the underlying letter, with the exception that ü is frequently sorted as y.

Languages that treat accented letters as variants of the underlying letter usually alphabetize words with such symbols immediately after similar unmarked words. in phone books or in author catalogues in libraries), umlauts are often treated as combinations of the vowel with a suffixed e; Austrian phone books now treat characters with umlauts as separate letters (immediately following the underlying vowel).