As of Unicode version 16.0, there are 155,063 characters with code points, covering 168 modern and historical scripts, as well as multiple symbol sets.
The nnnn or hhhh may be any number of digits and may include leading zeros.
The entity must either be predefined (built into the markup language) or explicitly declared in a Document Type Definition (DTD).
Footnotes: The Unicode Standard (version 16.0) classifies 1,487 characters as belonging to the Latin script.
96 characters; the 62 letters, and two ordinal indicators belong to the Latin script.
Other Brahmic and Indic scripts in Unicode include: 112 code points; 111 assigned characters; 24 in the MES-2 subset.