iswitchb-cannot-complete-hook

iswitchb-cannot-complete-hook is a variable defined in `iswitchb.el'.
Its value is

iswitchb-completion-help

• This variable may be risky if used as a file-local variable.

Documentation:
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.

You can customize this variable.