Yn (Ꙟ ꙟ) is an archaic Cyrillic letter. It was an innovation entirely unique to the Romanian Cyrillic alphabet, not appearing in any other Cyrillic alphabet. It was derived from the Cyrillic glyph big yus.
It was used in the Romanian Cyrillic alphabet, where it represented the sounds [ɨn], [ɨm], and [ɨ] at the beginning of words. In the 19th century, it was replaced in the Romanian alphabet by ⟨în⟩, ⟨îm⟩, or ⟨î⟩.
It was used interchangeably with big yus up until the years 1683-1688 when it began to only be used in word initial position.
Computing codes
As few fonts contain the appropriate glyphs, the Upwards Arrow (↑) is sometimes substituted. The notable fonts that have included this glyph are FreeSerif and Segoe UI (since Windows 8).