The Hangul Compatibility Jamo block spans U+3130–U+318F, 96 codepoints in Plane 0 (Basic Multilingual Plane). 94 are assigned in Unicode 16.0; the other 2 are reserved for future characters.
All of its characters belong to the Hangul script.
By general category: 94 other letters (Lo).
The first 94 arrived in Unicode 1.1 (1993).
94 characters here have compatibility decompositions: they are formatting variants of other characters and are replaced by them under NFKC and NFKD. See normalization.
94 characters are East Asian Wide or Fullwidth and take two columns in terminals.