U+0406 Cyrillic Capital Letter Byelorussian-Ukrainian I

The Wikipedia has the following information about this codepoint:

The dotted i (І і; italics: І і), also called decimal i (и десятеричное, after its former numeric value) or soft-dotted i, is a letter of the Cyrillic script. It commonly represents the close front unrounded vowel /i/, like the pronunciation of ⟨i⟩ in English "machine". It is used in the orthographies of Belarusian, Kazakh, Khakas, Komi, Carpathian Rusyn and Ukrainian and quite often, but not always, is the equivalent of the Cyrillic letter i (И и) as used in Russian and other languages. However, the letter І (⟨І⟩) was also used in Russian before the Bolshevik reform of 1918.

In Ukrainian, І is the twelfth letter of the alphabet and represents the sound [i] in writing. Ukrainian uses и to represent the sound [ɪ]. In Belarusian, I is the tenth letter of the alphabet. It represents [i]. The two Carpathian Rusyn standard varieties use і, и and ы for three different sounds: /i/, /ɪ/ and /ɨ/, respectively. In Komi, і occurs only after the consonants д, з, л, н, с, and т and does not palatalize them, while и does. In Kazakh and Khakas, і represents /ɘ/, as in "bit".

Just like the Latin letters I/i (and J/j), the dot above the letter appears only in its lowercase form and then only if that letter is not combined with a diacritic above it (notably the diaeresis, used in Ukrainian to note the letter yi of its alphabet, and the macron). Even when the lowercase form is present without any other diacritic, the dot is not always rendered in historic texts (the same historically applied to the Roman letters i and j). Some modern texts and font styles, except for cursive styles, still discard the "soft" dot on the lowercase letter, because the text is readable without it. However, the current official rules of Belarusian orthography (2008) state that the letter ⟨і⟩ is undotted in printed uppercase, but should be dotted in lowercase and in handwritten uppercase.