As of Unicode version 15.1, Cyrillic script is encoded across several blocks: Cyrillic: U+0400–U+04FF, 256 characters Cyrillic Supplement: U+0500–U+052F, 48 characters Cyrillic Extended-A: U+2DE0–U+2DFF, 32 characters Cyrillic Extended-B: U+A640–U+A69F, 96 characters Cyrillic Extended-C: U+1C80–U+1C8F, 9 characters Cyrillic Extended-D: U+1E030–U+1E08F, 63 characters Phonetic Extensions: U+1D2B, U+1D78, 2 Cyrillic characters Combining Half Marks: U+FE2E–U+FE2F, 2 Cyrillic charactersThe characters in the range U+0400–U+045F are basically the characters from ISO 8859-5 moved upward by 864 positions. Wikipedia