An NSEC-record links to the next record name in the zone (in DNSSEC sorting order) and lists the record types that exist for the record's name.
These records can be used by resolvers to verify the non-existence of a record name and type as part of DNSSEC validation.
NSEC-records have the following data elements:
Next domain name: The next record name in the zone (DNSSEC sorting order)
Record types: The DNS record types that exist for the name of this NSEC-record.
To add NSEC-records to a zone, use the DNSSEC Sign Zone function.
This record type is defined in RFC4034.