One particularly useful example of a noncharacter is the code point U+FFFE.

In graphonomics, the term glyph is used for a noncharacter, i.e.: either a subcharacter or multicharacter pattern.

If a stream of text contains this noncharacter, this is a good indication the text has been interpreted with the incorrect endianness.

Certain noncharacter code points are guaranteed never to be used for encoding characters, although applications may make use of these code points internally if they wish.

Martial, however, is as much a noncharacter as "A Few Days With Me" is a nonmovie.

In addition, there is a contiguous range of another 32 noncharacter code points in the BMP: U+FDD0.