Each element looks like (OPEN-CHAR CLOSE-CHAR) or (COMMAND-CHAR
OPEN-CHAR CLOSE-CHAR). The characters OPEN-CHAR and CLOSE-CHAR
of the pair whose key is equal to the last input character with
-or without modifiers, are inserted by `insert-pair'.")
+or without modifiers, are inserted by `insert-pair'.
+
+If COMMAND-CHAR is specified, it is a character that triggers the
+insertion of the open/close pair, and COMMAND-CHAR itself isn't
+inserted.")
(defun insert-pair (&optional arg open close)
"Enclose following ARG sexps in a pair of OPEN and CLOSE characters.