Unicode special code points

Unicode character (U+FEFF)

non-spacing character that modifies another character

non-printing format effector or control code, included in Unicode

Unicode control character; name is misnomer; has 2 functions: ① indicates that a pair of characters is a digraph for the purposes of ligation but not for collation; ② prevents canonical reordering of combining marks for e.g. Hebrew cantillation marks