"Toggle Show Paren mode.
When Show Paren mode is enabled, any matching parenthesis is highlighted
after `show-paren-delay' seconds of Emacs idle time.
-You must modify via \\[customize] for this variable to have an effect."
+This variable should be set only with \\[customize], which is equivalent
+to using the function `show-paren-mode'.
:set (lambda (symbol value)
(show-paren-mode (or value 0)))
:initialize 'custom-initialize-default