FFF0 Specials FFFF

Interlinear annotation

Used internally for Japanese Ruby (furigana), etc.

COMMENT_LINE { "bullet": "*", "text": "marks start of annotated text" }

COMMENT_LINE { "bullet": "*", "text": "marks start of annotating character(s)" }

COMMENT_LINE { "bullet": "*", "text": "marks end of annotation block" }

Replacement characters

COMMENT_LINE { "bullet": "*", "text": "used as placeholder in text for an otherwise unspecified object" }

COMMENT_LINE { "bullet": "*", "text": "used to replace an incoming character whose value is unknown or unrepresentable in Unicode" }

COMMENT_LINE { "bullet": "*", "text": "compare the use of 001A as a control character to indicate the substitute function" }

CROSS_REF { "name2": "uncertainty sign", "cp2": "2BD1" }

CROSS_REF { "name2": "negative squared question mark", "cp2": "1FBC4" }

Noncharacters

These codes are intended for process-internal uses.

COMMENT_LINE { "bullet": "*", "text": "may be used to detect byte order by contrast with FEFF" }

CROSS_REF { "name2": "zero width no-break space", "cp2": "FEFF" }