Specials characters supported by the STIX Two Math Regular font

Character	Image
REPLACEMENT CHARACTER (U+FFFD)

Count: 1

Character
INTERLINEAR ANNOTATION ANCHOR (U+FFF9)
INTERLINEAR ANNOTATION SEPARATOR (U+FFFA)
INTERLINEAR ANNOTATION TERMINATOR (U+FFFB)
OBJECT REPLACEMENT CHARACTER (U+FFFC)

Count: 4