letter "I" / "ı", with the absence of a tittle also on the lower case letter, represents the close back unrounded vowel , while "İ" / "i", with the inclusion of a tittle even on the capital letter, represents the close front unrounded vowel . This practice has carried over to several other Turkic languages, like the Azerbaijani alphabet, Crimean Tatar alphabet, and Tatar alphabet. In some of the Dene languages of the Northwest Territories in Canada, specifically North Slavey, South Slavey, Tłı̨chǫ and Dëne Sųłıné, all instances of i are undotted to avoid confusion with tone-marked vowels í or ì. The other Dene language of the Northwest Territories, Gwich’in, always includes the tittle on lowercase i. There is only one letter I in Irish, but i is undotted in the traditional uncial Gaelic script to avoid confusion of the tittle with the buailte overdot found over consonants. Modern texts replace the buailte with the letter h, and use the same antiqua-descendant fonts, which have a tittle, as other Latin-alphabet languages. However, bilingual road signs use dotless i in lowercase Irish text to better distinguish i from í. The letter "j" is not used in Irish other than in foreign words. In most Latin-based orthographies, the lowercase letter i conventionally has its dot replaced when a diacritical mark atop the letter, such as an acute or grave accent, is placed. The tittle is sometimes retained in some languages. In some Baltic languages sources, the lowercase letter i sometimes retains a tittle even when accented. In Vietnamese in the 17th century, the tittle is preserved atop ỉ and ị but not ì and í, as seen in the seminal quốc ngữ reference Dictionarium Annamiticum Lusitanum et Latinum. In modern Vietnamese, a tittle can be seen in ì, ỉ, ĩ, and í in cursive handwriting and some signage. This detail rarely occurs in computers and on the Internet, due to the obscurity of language-specific fonts. In any case, the tittle is always retained in ị. Phrases It is thought that the phrase "to a T" is derived from the word tittle because long before "to a T" became popular, the phrase "to a tittle" was used. The phrase "to dot one's I's and cross one's T's" is used figuratively to mean "to put the finishing touches to" or "to be thorough". References Sources Dictionary.com – Tittle External links Henry George Liddell, Robert