Time in seconds of being unable to query the primary server after which secondary servers should stop serving the zone.
The time to live (TTL) for negative caching of records within the zone.
The primary nameserver, which may be used for outbound zone transfers.
Time in seconds after which secondary servers should re-check the SOA record to see if the zone has been updated.
Time in seconds after which secondary servers should retry queries after the primary server was unresponsive.
The email address of the zone administrator, with the first label representing the local part of the email address.
The time to live (TTL) of the SOA record itself.