+(defcustom iswitchb-cannot-complete-hook 'iswitchb-completion-help
+ "*Hook run when `iswitchb-complete' can't complete any more.
+The most useful values are `iswitchb-completion-help', which pops up a
+window with completion alternatives, or `iswitchb-next-match' or
+`iswitchb-prev-match', which cycle the buffer list."
+ :type 'hook
+ :group 'iswitchb)
+