Uppercase Cyrillic I with a macron (bar) above, a long i used in Tajik and some other languages.
U+04E1CYRILLIC SMALL LETTER ABKHASIAN DZEU+04E3CYRILLIC SMALL LETTER I WITH MACRONU+04E0CYRILLIC CAPITAL LETTER ABKHASIAN DZEU+04E4CYRILLIC CAPITAL LETTER I WITH DIAERESISU+04DFCYRILLIC SMALL LETTER ZE WITH DIAERESISU+04E5CYRILLIC SMALL LETTER I WITH DIAERESISU+04DECYRILLIC CAPITAL LETTER ZE WITH DIAERESISU+04E6CYRILLIC CAPITAL LETTER O WITH DIAERESISU+04DDCYRILLIC SMALL LETTER ZHE WITH DIAERESISU+04E7CYRILLIC SMALL LETTER O WITH DIAERESISU+04DCCYRILLIC CAPITAL LETTER ZHE WITH DIAERESISU+04E8CYRILLIC CAPITAL LETTER BARRED O256 characters in the Cyrillic Unicode block, from number 227.
U+04E2CYRILLIC CAPITAL LETTER I WITH MACRONU+04E3CYRILLIC SMALL LETTER I WITH MACRONU+04E4CYRILLIC CAPITAL LETTER I WITH DIAERESISU+04E5CYRILLIC SMALL LETTER I WITH DIAERESISU+04E6CYRILLIC CAPITAL LETTER O WITH DIAERESISU+04E7CYRILLIC SMALL LETTER O WITH DIAERESISU+04E8CYRILLIC CAPITAL LETTER BARRED OU+04E9CYRILLIC SMALL LETTER BARRED OU+04EACYRILLIC CAPITAL LETTER BARRED O WITH DIAERESISU+04EBCYRILLIC SMALL LETTER BARRED O WITH DIAERESISU+04ECCYRILLIC CAPITAL LETTER E WITH DIAERESISU+04EDCYRILLIC SMALL LETTER E WITH DIAERESISU+04EECYRILLIC CAPITAL LETTER U WITH MACRONU+04EFCYRILLIC SMALL LETTER U WITH MACRONU+04F0CYRILLIC CAPITAL LETTER U WITH DIAERESISU+04F1CYRILLIC SMALL LETTER U WITH DIAERESISU+04F2CYRILLIC CAPITAL LETTER U WITH DOUBLE ACUTEU+04F3CYRILLIC SMALL LETTER U WITH DOUBLE ACUTEU+04F4CYRILLIC CAPITAL LETTER CHE WITH DIAERESISU+04F5CYRILLIC SMALL LETTER CHE WITH DIAERESISU+04F6CYRILLIC CAPITAL LETTER GHE WITH DESCENDERU+04F7CYRILLIC SMALL LETTER GHE WITH DESCENDERU+04F8CYRILLIC CAPITAL LETTER YERU WITH DIAERESISU+04F9CYRILLIC SMALL LETTER YERU WITH DIAERESISU+04FACYRILLIC CAPITAL LETTER GHE WITH STROKE AND HOOKU+04FBCYRILLIC SMALL LETTER GHE WITH STROKE AND HOOKU+04FCCYRILLIC CAPITAL LETTER HA WITH HOOKU+04FDCYRILLIC SMALL LETTER HA WITH HOOKU+04FECYRILLIC CAPITAL LETTER HA WITH STROKEU+04FFCYRILLIC SMALL LETTER HA WITH STROKE