Í, í (i-acute) is a letter in the Faroese, Hungarian, Icelandic, Czech, Slovak, and Tatar languages, where it often indicates a long /i/ vowel. This letter also appears in Catalan, Irish, Occitan, Portuguese, Spanish, Galician, Leonese, Navajo, and Vietnamese language as a variant of the letter “i”. In Latin, the long i ⟨ꟾ⟩ is used instead of ⟨í⟩ for a long i-vowel.
Usage in various languages 
Í is the 11th letter of the Faroese alphabet and represents /ʊi/.
Hungarian, Icelandic, Czech and Slovak 
Í is the 14th letter of the Tatar alphabet (based on Zamanälif). It represents /ɨɪ/.
In Vietnamese alphabet í is the sắc tone (high-rising tone) of “i”.
In Chinese pinyin í is the yángpíng tone (阳平, high-rising tone) of “i”.
Portuguese, Spanish 
In Portuguese and Spanish, the "í" isn't considered a letter, but the letter "i" with an accent. It's used to denote an "i" syllable with abnormal stress.
Character mappings 
|Unicode name||LATIN CAPITAL LETTER I WITH ACUTE||LATIN SMALL LETTER I WITH ACUTE|
|UTF-8||195 141||C3 8D||195 173||C3 AD|
|Numeric character reference||Í||Í||í||í|
|Named character reference||Í||í|
See also 
- Omniglot - writing systems & languages of the world
Letter I with diacritics
|Í í||Ì ì||Ĭ ĭ||Î î||Ǐ ǐ||Ïï||Ḯḯ||Ĩĩ||Į į||Ī ī||Ỉ ỉ||Ȉ ȉ||Ȋ ȋ||Ị ị||Ḭ ḭ||Ɨ ɨ||ᵻ||ᶖ||İ i||I ı||ꟾ|
Letters using acute accent ( ◌́ )