The CJK Unified Ideographs Extension H block spans U+31350–U+323AF, 4,192 codepoints in Plane 3 (Tertiary Ideographic Plane). Every one of them is assigned in Unicode 16.0.

All of its characters belong to the Han script.

By general category: 4,192 other letters (Lo).

The first 4,192 arrived in Unicode 15.0 (2022).

4,192 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.