Do not run the task during the current installation request.
This can be used to skip running an installation task when certain conditions are met, even though the task may still show on the list of installation tasks presented to the user. For example, the Drupal installer uses this flag to skip over the database configuration form when valid database connection information is already available from settings.php. It also uses this flag to skip language import tasks when the installation is being performed in English.
define('INSTALL_TASK_SKIP', 1);