[3][4][5] Most of them are intended as representations of faces, although some of them include hand gestures or non-human characters (a horned "imp", monkeys, cartoon cats).
The reason for its adoption was largely for compatibility with a de facto standard that had been established by the early 2000s by Japanese telephone carriers, encoded in unused ranges with lead bytes 0xF5 to 0xF9 of the Shift JIS standard.
Example: The Miscellaneous Symbols and Pictographs block has 54 emoji that represent people or body parts.
The draft document suggesting the introduction of this system for the representation of "human diversity" was submitted in 2015 by Mark Davis of Google and Peter Edberg of Apple Inc.[8] Five symbol modifier characters were added with Unicode 8.0 to provide a range of skin tones for human emoji.
The following Unicode-related documents record the purpose and process of defining specific characters in the Emoticons block: