U+012C Ĭ and U+012D ĭ are the only characters from Latin Extended-A not encoded so far. Its most common uses seems to be indicating vowel length in Latin and in phonetic transcriptions in American dictionaries, but it’s also used in one orthography of Crimean Tatar, and in some Cyrillic transliterations, corresponding to й.
U+012C Ĭ and U+012D ĭ are the only characters from Latin Extended-A not encoded so far. Its most common uses seems to be indicating vowel length in Latin and in phonetic transcriptions in American dictionaries, but it’s also used in one orthography of Crimean Tatar, and in some Cyrillic transliterations, corresponding to й.