The Ideographic Description Characters block spans U+2FF0–U+2FFF, 16 codepoints in Plane 0 (Basic Multilingual Plane). Every one of them is assigned in Unicode 16.0.
All of its characters have the script value Common: they are shared across writing systems rather than tied to one.
By general category: 16 other symbols (So).
The first 12 arrived in Unicode 3.0 (1999); later additions came in 15.1 (4).
16 characters are East Asian Wide or Fullwidth and take two columns in terminals.