I (Cyrillic)

Both remained in the alphabetical repertoire because they represented different numbers in the Cyrillic numeral system: eight and ten.

Other modern orthographies for Slavic languages eliminated one of the two letters in alphabet reforms of the 19th or the 20th centuries.

The middle stroke was later turned counterclockwise, which resulted in the modern form resembling a mirrored capital Latin letter N ⟨N⟩ and so ⟨И⟩ is used in faux Cyrillic typography.

However, unlike other "soft" vowels (е, ё, ю and я), и in isolation is not preceded by the /j/ semivowel.

⟨И⟩ was used significantly less in Russian before the Bolshevik reform of 1918: According to critics of the Bolshevik reform, the choice of Ии as the only letter to represent that side and the removal of Іі defeated the purpose of 'simplifying’ the language, as Ии occupies more space and, furthermore, is sometimes indistinguishable from Шш.

It represents the sound /i/ and also occurs with a grave accent, ѝ, to distinguish orthographically the conjunction ⟨и⟩ ("and") and the short form of the indirect object ⟨ѝ⟩ ("her").

[1][2] Due to its close resemblance to the Latin capital letter N, specifically as a "flipped" or "reflected" version of it, it is sometimes used stylistically as a replacement for N. This is commonly seen in Faux Cyrillic.

The hard rock band Linkin Park have also used the glyph, particularly on the cover of their debut album Hybrid Theory.

Special Serbian texts also use ⟨и⟩ with a macron to represent long unstressed variant of the sound.

None of those combinations is considered to be a separate letter of respective alphabet, but one of them (⟨Ѝ⟩) has an individual code position in Unicode.

The form has been used regularly in Church Slavonic since the 16th century, but it officially became a separate letter of alphabet only much later (in Russian in 1918).

In early Russian typewriters like this one, there was no key for the digit 1, so the dotted І was used instead. Following the Russian alphabet reform of 1918, a 1 key was added.
The logo of Nine Inch Nails