When used as a diacritic mark, the term dot is usually reserved for the Interpunct ( · ), or to the glyphs 'combining dot above' ( ◌̇ ) and 'combining dot below' ( ◌̣ )
which may be combined with some letters of the extended Latin alphabets in use in Central European languages and Vietnamese.
Traditional Irish typography, where the dot denotes lenition, and is called a ponc séimhithe or buailte "dot of lenition": ḃ ċ ḋ ḟ ġ ṁ ṗ ṡ ṫ. Alternatively, lenition may be represented by a following letter h, thus: bh ch dh fh gh mh ph sh th. In Old Irish orthography, the dot was used only for ḟ ṡ, while the following h was used for ch ph th; lenition of other letters was not indicated. Later the two systems spread to the entire set of lenitable consonants and competed with each other. Eventually the standard practice was to use the dot when writing in Gaelic script and the following h when writing in antiqua. Thus ċ and ch represent the same phonetic element in Modern Irish.
Lithuanian: ė is pronounced as [eː], compared to ę, which is pronounced a lower [ɛː] (formerly nasalised), or e, pronounced [ɛ, ɛː].
In the Canadian Aboriginal Syllabics orthography for the Cree, Ojibwe, and Inuktitut languages, a dot above a symbol signifies that the symbol's vowel should be a long vowel—the equivalent effect using the Roman orthography is achieved by doubling the vowel (ᒥ = mi, ᒦ = mii ), placing a macron over the vowel (ᑲ = ka, ᑳ = kā), or placing a circumflex over the vowel (ᓄ = no, ᓅ = nô).
In Turkish, the dot above lowercase i and j (and uppercase İ) is not regarded as an independent diacritic but as an integral part of the letter. It is called a tittle. I without an overdot is a separate letter.
In Romagnol, ẹ ọ are used to represent [e, o], e.g. Riminese dialect fradẹll, ọcc [fraˈdell, ˈotʃː] "brothers, eyes".
In academic notation of Old Latin, ẹ̄ (e with underdot and macron) represents the long vowel, probably /eː/, that developed from the early Old Latin diphthong ei. This vowel usually became ī in Classical Latin.
In academic transcription of Vulgar Latin, used in describing the development of the Romance languages, ẹ and ọ represent the close-mid vowels /e/ and /o/, in contrast with the open-mid vowels /ɛ/ and /ɔ/, which are represented as e and o with ogonek (ę ǫ).
Vietnamese: The nặngtone (low, glottal) is represented with a dot below the base vowel: ạ ặ ậ ẹ ệ ị ọ ộ ợ ụ ự ỵ.
In Yoruba, the dot (or alternatively a small vertical line) is used below the o for an "open-o" sound, the e for an "open-e," and the s for an "sh" sound (ẹ, ọ, ṣ). The marking distinguishes these from the unmarked characters since the sound differences are meaningful.
In Igbo, an underdot can be used on i, o, and u to make ị, ọ, and ụ. The underdot symbolizes a reduction in the vowel height.