Dotted and dotless I

In some fonts, if the lowercase letters fi are placed adjacently, the dot-like upper end of the f would fall inconveniently close to the dot of the i, and therefore a ligature glyph is provided with the top of the f extended to serve as the dot of the i. A similar ligature for ffi is also possible. Since the forms without ligatures are unattractive and the ligatures make the i dotless, such fonts are not appropriate for use in a Turkish setting. However, the fi ligatures of some fonts do not merge the letters and instead space them next to each other, with the dot on the i remaining. Such fonts are appropriate for Turkish, but the writer must be careful to be consistent in the use of ligatures.

In normal typography, when lower case i is combined with other diacritics, the dot is generally removed before the diacritic is added; however, Unicode still lists the equivalent combining sequences as including the dotted i, since logically it is the normal dotted i character that is being modified.

Most Unicode software uppercases ı to I and lowercases İ to i, but, unless specifically configured for Turkish, it lowercases I to i and uppercases i to I. Thus uppercasing then lowercasing, or vice versa, changes the letters.

In the Microsoft Windows SDK, beginning with Windows Vista, several relevant functions have a NORM_LINGUISTIC_CASING flag, to indicate that for Turkish and Azerbaijani locales, I should map to ı and i to İ.

In the LaTeX typesetting language the dotless ı can be written with the backslash-i command: \i. The İ can be written using the normal accenting method (i.e. \.{I}).

Dotless ı (and dotted capital İ) is handled problematically in the Turkish locales of several software packages, including Oracle DBMS, PHP, Java (software platform),[2][3] and Unixware 7, where implicit capitalization of names of keywords, variables, and tables has effects not foreseen by the application developers. The C or US English locales do not have these problems. The .NET Framework has special provisions to handle the 'Turkish i'.[4]

Many cellphones available in Turkey (as of 2008) lacked a proper localization, which led to replacing ı by i in SMS, sometimes severely distorting the sense of a text. In one instance, a miscommunication played a role in the deaths of Emine and Ramazan Çalçoban in 2008.[5][6] A common substitution is to use the character 1 for dotless ı. This is also common in Azerbaijan (see also translit), but the meaning of words is generally understood.

John Cowan proposed disunification of plain Ii and capital letter dotless I and small letter I with dot above to make the casing more consistent.[7] The UTC had previously rejected a similar proposal because it would corrupt mapping from character sets with dotted and dotless I and corrupt data in these languages.[8]

Error when displaying dotted İ as a dotless I while translating from Turkish to Polish

In some Ectaco translators, the letter İ was also treated as I (e.g. TRAFIK ⟨traffic⟩, when it's normally TRAFİK).

A plaque in Crimean Tatar Latin script in Bakhchisaray with both dotted and dotless i.

Dotted and dotless i are used in several other writing systems for Turkic languages:

• Azerbaijani: The Azerbaijani Latin alphabet used in Azerbaijan is modeled after Turkish since 1991.
• Karakalpak: The official Karakalpak alphabet approved in 2016 uses ⟨ı⟩ as the lowercase form of ⟨Í⟩.
• Kazakh: The 2018 Latin orthography uses dotless I to represent [j] and also to represent [i] in Russian loanwords, contrary to the letter's use in other Turkic languages. A Turkish-style alphabet, however, is used by linguists, the Kazakh Wikipedia (in addition to Cyrillic and Arabic) and the Kazakh diaspora in the West and Turkey. Dotted I in the Kazakh orthography represents [i] in native Kazakh words - its capital form was still dotless until 2019. In the original 2017 proposal, /j/ and (in Russian loanwords) /i/ were represented by the sequence i'. [/ə/], represented by dotless I in most Turkic orthographies, is instead represented by y. In 2019, under president Tokayev's suggestion, the upper-case İ was also introduced, to finalize replacing of upper-case Cyrillic І which mostly represents [ɪ].
• Volga Tatar: The Tatar alphabet in Russia is officially Cyrillic due to the requirements of Russian federal law. Several Romanization schemes exist, which are used on the Internet and some printed publication. Most of them are modelled in different ways on Turkish and employ dotted and dotless I, while some also use I with acute (Í), although for different phonemes. The only Latin alphabet that ever had official status in Tatarstan, Yañalif, used the character Ь instead of dotless i.
• Crimean Tatar: Cyrillic script is officially used for Crimean Tatar in the Russian Republic of Crimea. The Latin alphabet, which includes both dotted and dotless I, is still used, but is not the official script for the language.

The dotless ı may also be used as a stylistic variant of the dotted i, without there being any meaningful difference between them. This is common in Irish, for example. See Tittle.

Both the dotted and dotless I can be used in transcriptions of Rusyn to allow distinguishing between the letters Ы and И, which would otherwise be both transcribed as "y", despite representing different phonemes. Under such transcription the dotted İ would represent the Cyrillic І, and the dotless I would represent either Ы or И, with the other being represented by "Y".

• African reference alphabet, where a similar situation occurs, albeit with the serifs rather than the tittles
• Tittle: the dot above "i" and "j" in most of the Latin scripts
• Yery (ы) — a letter used to represent [ɯ] in Turkic languages with Cyrillic script, and the similar [ɨ] in Russian

• http://www.unicode.org/charts/PDF/U0100.pdf
• Tex Texin, Internationalization for Turkish: Dotted and Dotless Letter "I", accessed 15 Nov 2005