2.1.3 [ISO10646] Section D.4, Mapping from UCS-4 form to UTF-8 form
Table D.4 defines in mathematical notation the mapping from the UCS-4 coded representation form to the UTF-8 coded representation form.
All Document Modes (All Versions)
Characters encoded as UTF-8 that have values beyond the
range of what can be represented by UTF-16 (up to
have each byte decoded as a separate character.