mm-char-or-char-int-p
mm-char-or-char-int-p is an alias for `characterp' in `mm-util.el
'.
(mm-char-or-char-int-p OBJECT)
Return non-nil if OBJECT is a character.
In Emacs Lisp, characters are represented by character codes, which
are non-negative integers. The function `max-char' returns the
maximum character code.