*** The function forward-char moves over characters, and therefore
(forward-char 1) may increase point by more than 1 if it moves over a
multibyte character. Likewise, delete-char always deletes a
character, which may be more than one buffer position.
This means that some Lisp programs, which assume that a character is always one buffer position, need to be changed.
However, all ASCII characters are always one buffer position.