Undefined Character (U+1DFFD)

Plane:	Supplementary Multilingual Plane, U+10000 - U+1FFFF^[1]
HTML Entity:	`𝿽` `𝿽`
UTF-8 Encoding:	`0xF0 0x9D 0xBF 0xBD`
UTF-16 Encoding:	`0xD837 0xDFFD`
UTF-32 Encoding:	`0x0001DFFD`

References