The CJK Compatibility Ideographs Supplement block spans U+2F800–U+2FA1F, 544 codepoints in Plane 2 (Supplementary Ideographic Plane). 542 are assigned in Unicode 16.0; the other 2 are reserved for future characters.
All of its characters belong to the Han script.
By general category: 542 other letters (Lo).
The first 542 arrived in Unicode 3.1 (2001).
542 characters here are precomposed and have canonical decompositions, so NFD splits them into a base letter plus combining marks. See normalization.
542 characters are East Asian Wide or Fullwidth and take two columns in terminals.
Because it lies outside the BMP, every character here takes four bytes in UTF-8 and a surrogate pair in UTF-16.