D83C

D83C is a hexadecimal UTF-16 code unit used as the high surrogate in surrogate pairs that encode Unicode characters outside the Basic Multilingual Plane (BMP). In UTF-16, characters with code points above U+FFFF are represented by two 16‑bit code units: a high surrogate in the range U+D800 to U+DBFF and a low surrogate in the range U+DC00 to U+DFFF. The specific value 0xD83C is one such high surrogate, and when paired with an appropriate low surrogate, it produces a single code point in the supplementary planes (U+10000 to U+10FFFF).

The combination of D83C with various low surrogates yields many different characters, particularly emoji and other symbols that reside outside the BMP. For example, the pair D83C DC04 encodes the Unicode code point U+1F004 (mahjong red dragon). Another common pattern is the use of D83C followed by different low surrogates to form sequences that render as two-part emoji or symbol sequences, such as those used for country flags that are represented by two regional indicator symbols (for instance, D83C DDFA and D83C DDF8 together correspond to the United States flag’s two regional indicators).

Standing alone, the code unit D83C has no independent character meaning; its interpretation depends on the accompanying low surrogate to form a valid Unicode code point. In programming and text processing, D83C frequently appears in escaped or encoded forms, such as the Unicode escape sequence \uD83C\uXXXX in languages that use UTF-16.

In summary, D83C is a high surrogate used in UTF-16 to encode supplementary characters, most prominently many emoji, when paired with a suitable low surrogate.