The Cyrillic Supplement block spans U+0500–U+052F, 48 codepoints in Plane 0 (Basic Multilingual Plane). Every one of them is assigned in Unicode 16.0.
All of its characters belong to the Cyrillic script.
By general category: 24 uppercase letters (Lu), 24 lowercase letters (Ll).
The first 16 arrived in Unicode 3.2 (2002); later additions came in 5.0 (4), 5.1 (16), 5.2 (2), 6.0 (2), 7.0 (8).