U+1FC3 "ῃ" Greek Small Letter Eta with Ypogegrammeni Unicode Character

U+1FC3 "ῃ" Greek Small Letter Eta with Ypogegrammeni is a composite glyph used in polytonic Greek writing, specifically representing the vowel sound eta (η) combined with an iota subscript (ypogegrammeni) written beneath it. This character typically appears in ancient and liturgical Greek texts to indicate a long diphthong where the iota is not pronounced but historically marks a grammatical case or verb form, such as in the dative singular of certain nouns or the subjunctive mood of verbs. It is encoded as a single precomposed character for compatibility with legacy systems, though modern Unicode also supports representing it as a sequence of eta followed by the combining iota subscript (U+0345).