0xD83C
0xD83C is the hexadecimal value of a high surrogate code unit in UTF-16 encoding. It is not a complete character on its own; rather, it forms the first half of a surrogate pair that encodes code points outside the Basic Multilingual Plane (BMP), specifically those above U+FFFF. In UTF-16, characters in the supplementary planes are represented by two 16-bit code units: a high surrogate in the range U+D800 to U+DBFF (such as 0xD83C) followed by a low surrogate in the range U+DC00 to U+DFFF (for example 0xDF0E). The resulting code point can be computed from both halves, and many common emoji and other symbols are encoded this way.
An illustrative example is the pair 0xD83C 0xDF0E, which encodes the Unicode code point U+1F30E, the Earth
Because surrogate pairs are two-code-unit sequences, malformed pairs (for example, a high surrogate not followed by
Summary: 0xD83C is a high surrogate used in UTF-16 to encode many supplementary characters, most famously visible