WordPress at a glance
action is not described

delete_usermeta action-hook . WP 1.0

Usage

add_action( 'delete_usermeta', 'action_function_name_3920', 10, 4 );
function action_function_name_3920( $umeta_id, $user_id, $meta_key, $meta_value ){
	// action...
}
$umeta_id
-
$user_id
-
$meta_key
-
$meta_value
-

Where the hook is called

delete_usermeta()
wp-includes/deprecated.php 2233
do_action( 'delete_usermeta', $cur->umeta_id, $user_id, $meta_key, $meta_value );

Where the hook is used (in WP core)

Does not used.