The Glagolitic Supplement block spans U+1E000–U+1E02F, 48 codepoints in Plane 1 (Supplementary Multilingual Plane). 38 are assigned in Unicode 16.0; the other 10 are reserved for future characters.
All of its characters belong to the Glagolitic script.
By general category: 38 non-spacing marks (Mn).
The first 38 arrived in Unicode 9.0 (2016).
Most characters here are combining marks. See combining diacritical marks.
Because it lies outside the BMP, every character here takes four bytes in UTF-8 and a surrogate pair in UTF-16.