WordPress at a glance
action is not described

wp_dashboard_setup action-hook . WP 2.5.0

Fires after core widgets for the admin dashboard have been registered.

Usage

add_action( 'wp_dashboard_setup', 'action_function_name_4608' );
function action_function_name_4608(){
	// action...
}

Where the hook is called

wp_dashboard_setup()
wp_dashboard_setup
wp-admin/includes/dashboard.php 99
do_action( 'wp_dashboard_setup' );

Where the hook is used (in WP core)

Does not used.