Undefined Character (U+1FFFF)

Plane:	Supplementary Multilingual Plane, U+10000 - U+1FFFF^[1]
HTML Entity:	`🿿` `🿿`
UTF-8 Encoding:	`0xF0 0x9F 0xBF 0xBF`
UTF-16 Encoding:	`0xD83F 0xDFFF`
UTF-32 Encoding:	`0x0001FFFF`

References