The Sutton SignWriting block spans U+1D800–U+1DAAF, 688 codepoints in Plane 1 (Supplementary Multilingual Plane). 672 are assigned in Unicode 16.0; the other 16 are reserved for future characters.
All of its characters belong to the SignWriting script.
By general category: 540 other symbols (So), 127 non-spacing marks (Mn), 5 other punctuation (Po).
The first 672 arrived in Unicode 8.0 (2015).
Because it lies outside the BMP, every character here takes four bytes in UTF-8 and a surrogate pair in UTF-16.