The code for set message is called in 3 places. It can be using the latest me...

The code for set message is called in 3 places. It can be using the latest message function, search404_error_message()
drupal_set_message(t('The page you requested does not exist. For your convenience, a search was performed using the query %keys.', array('%keys' => check_plain($keys))), 'error');