Allow users to park subdomains of the server’s hostname main domain.
Allow domain parking across accounts [?]
Allow users to park domains (including creation of addon domains) on top of domains owned by other users. Not recommended.
Allow Remote Domains [?]
Allow creation of parked/addon domains that resolve to other servers (e.g. domain transfers) This can be a major security problem. If you must have it enabled, be sure not to allow users to park common Internet domains.
Allow resellers to create accounts with subdomains of the server’s hostname main domain.
Allow unregistered domains [?]
Allow creation of parked/addon domains that are not registered.