131: How do I tell what characters my function or arrow keys emit?
  
  Use this function by Randal L. Schwartz <merlyn@iwarp.intel.com>:
  
    (defun see-chars ()
      "Displays characters typed, terminated by a 3-second timeout."
      (interactive)
      (let ((chars "")
	    (inhibit-quit t))
	(message "Enter characters, terminated by 3-second timeout.")
	(while (not (sit-for 3))
	  (setq chars (concat chars (list (read-char)))
		quit-flag nil))		; quit-flag maybe set by C-g
	(message "Characters entered: %s" (key-description chars))))
  
  Alternatively, use the "C-h l" view-lossage command, which will display
  the last 100 characters Emacs has seen in its input stream.  Kevin
  Gallagher <kgallagh@digi.lonestar.org> suggests typing some unique string
  like "wxyz", typing the key in question, then typing "C-h l".  The
  characters that appear between "wxyz" and "C-h l" were generated by the
  key.