The Symbols for Legacy Computing block spans U+1FB00–U+1FBFF, 256 codepoints in Plane 1 (Supplementary Multilingual Plane). 249 are assigned in Unicode 16.0; the other 7 are reserved for future characters.
All of its characters have the script value Common: they are shared across writing systems rather than tied to one.
By general category: 239 other symbols (So), 10 decimal digits (Nd).
The first 212 arrived in Unicode 13.0 (2020); later additions came in 16.0 (37).
Because it lies outside the BMP, every character here takes four bytes in UTF-8 and a surrogate pair in UTF-16.