Undefined Character (U+10EFF)

Plane:	Supplementary Multilingual Plane, U+10000 - U+1FFFF^[1]
HTML Entity:	`𐻿` `𐻿`
UTF-8 Encoding:	`0xF0 0x90 0xBB 0xBF`
UTF-16 Encoding:	`0xD803 0xDEFF`
UTF-32 Encoding:	`0x00010EFF`

References