``U+FEFF``. This character can be prepended to every ``UTF-16`` or ``UTF-32``
byte sequence. The byte swapped version of this character (``0xFFFE``) is an
illegal character that may not appear in a Unicode text. So when the
-first character in an ``UTF-16`` or ``UTF-32`` byte sequence
+first character in a ``UTF-16`` or ``UTF-32`` byte sequence
appears to be a ``U+FFFE`` the bytes have to be swapped on decoding.
Unfortunately the character ``U+FEFF`` had a second purpose as
a ``ZERO WIDTH NO-BREAK SPACE``: a character that has no width and doesn't allow