Optional[customOptional[unknownSpecifies TTL, in seconds, for caching NXDOMAIN ("record not found") DNS responses from this zone (negative caching)
Set this TTL to a low value if you frequently delete and recreate records instead of updating them
Note: Values of less than 5 will be ignored, and a default negative caching TTL will be used instead
Custom SOA (Start of Authority) record specification for the zone