Specials characters supported by the Serif.plain font

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

Count: 5

Character

Count: 0