SPF : SPF record (RFC 4408)
Specified as part of the SPF protocol, as an alternative to storing SPF data in TXT records. Uses the same format as the TXT record.

TKEY : Transaction Key (RFC 2930)
One way of providing a key to be used with TSIG

TSIG : Transaction Signature (RFC 2845)
Record that supports one set of security mechanisms for DNS. Used to secure communication between DNS resolvers and Name servers, in contrast to DNSSEC, which secures the actual DNS records from the authoritative name server.

SRV : Service locator (RFC 2782)
Generalized service location record, used for newer protocols instead of creating protocol-specific records such as MX.

NS : name server record (RFC 1035)
Delegates a DNS zone to use the given authoritative name servers

RRSIG : DNSSEC signature (RFC 4034)
Signature for a DNSSEC-secured record set. Uses the same format as the SIG record.

SSHFP : SSH Public Key Fingerprint (RFC 4255)
Resource record for publishing SSH public host key fingerprints in the DNS System, in order to aid in verifying the authenticity of the host.

SOA : start of authority record (RFC 1035)
Specifies authoritative information about a DNS zone, including the primary name server, the email of the domain administrator, the domain serial number, and several timers relating to refreshing the zone.

DLV : DNSSEC Lookaside Validation record (RFC 4431)
For publishing DNSSEC trust anchors outside of the DNS delegation chain. Uses the same format as the DS record. RFC 5074 describes a way of using these records.

A : address record (RFC 1035)
Returns a 32-bit IPv4 address, most commonly used to map hostnames to an IP address of the host, but also used for DNSBLs, storing subnet masks in RFC 1101, etc.

* : All cached records (RFC 1035)
Returns all records of all types known to the name server. If the name server does not have any information on the name, the request will be forwarded on. The records returned may not be complete. For example, if there is both an A and an MX for a name, but the name server has only the A record cached, only the A record will be returned.

TXT : Text record (RFC 1035)
Originally for arbitrary human-readable text in a DNS record. Since the early 1990s, however, this record more often carries machine-readable data, such as specified by RFC 1464, opportunistic encryption, Sender Policy Framework, DomainKeys, DNS-SD, etc.

NSEC3 : NSEC record version 3 (RFC 5155)
An extension to DNSSEC that allows proof of nonexistence for a name without permitting zonewalking

DHCID : DHCP identifier (RFC 4701)
Used in conjunction with the FQDN option to DHCP

AFSDB : AFS database record (RFC 1183)
Location of database servers of an AFS cell. This record is commonly used by AFS clients to contact AFS cells outside their local domain. A subtype of this record is used by the obsolete DCE/DFS file system.

HIP : Host Identity Protocol (RFC 5205)
Method of separating the end-point identifier and locator roles of IP addresses.

MX : mail exchange record (RFC 1035)
Maps a domain name to a list of mail exchange servers for that domain

NSEC3PARAM : NSEC3 parameters (RFC 5155)
Parameter record for use with NSEC3