Undefined Character (U+1DFF9)

Plane:	Supplementary Multilingual Plane, U+10000 - U+1FFFF^[1]
HTML Entity:	`𝿹` `𝿹`
UTF-8 Encoding:	`0xF0 0x9D 0xBF 0xB9`
UTF-16 Encoding:	`0xD837 0xDFF9`
UTF-32 Encoding:	`0x0001DFF9`

References