The Pahawh Hmong block spans U+16B00–U+16B8F, 144 codepoints in Plane 1 (Supplementary Multilingual Plane). 127 are assigned in Unicode 16.0; the other 17 are reserved for future characters.
All of its characters belong to the Pahawh Hmong script.
By general category: 88 other letters (Lo), 10 decimal digits (Nd), 7 non-spacing marks (Mn), 7 other numbers (No), 6 other punctuation (Po), plus smaller groups.
The first 127 arrived in Unicode 7.0 (2014).
Because it lies outside the BMP, every character here takes four bytes in UTF-8 and a surrogate pair in UTF-16.