WordPress at a glance
action is not described

(hook) action-hook . WP 2.1.0

Fires scheduled events.

Usage

add_action( '(hook)', 'action_function_name_5486' );
function action_function_name_5486( $hook ){
	// action...
}
$hook(string)
Name of the hook that was scheduled to be fired.

Where the hook is called

In file: /wp-cron.php
(hook)
wp-cron.php 126
do_action_ref_array( $hook, $v['args'] );
woocommerce/includes/libraries/action-scheduler/classes/ActionScheduler_Action.php 22
return do_action_ref_array($this->get_hook(), $this->get_args());

Where the hook is used (in WP core)

Does not used.