CERT : Certificate record (RFC 4398)
Stores PKIX, SPKI, PGP, etc.

KEY : Key record (RFC 4034)
Used only for TKEY (RFC 2930). Before RFC 3755 was published, this was also used for DNSSEC, but DNSSEC now uses DNSKEY.

PTR : pointer record (RFC 1035)
Pointer to a canonical name. Unlike a CNAME, DNS processing does NOT proceed, just the name is returned. The most common use is for implementing reverse DNS lookups, but other uses include such things as DNS-SD.

IPSECKEY : IPSEC Key (RFC 4025)
Key record that can be used with IPSEC

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.

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

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.

IXFR : Incremental Zone Transfer (RFC 1995)
Requests a zone transfer of the given zone but only differences from a previous serial number. This request may be ignored and a full (AXFR) sent in response if the authoritative server is unable to fulfill the request due to configuration or lack of required deltas.

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

DS : Delegation signer (RFC 4034)
The record used to identify the DNSSEC signing key of a delegated zone

TA : DNSSEC Trust Authorities (None)
Part of a deployment proposal for DNSSEC without a signed DNS root. See the IANA database and Weiler Spec] for details. Uses the same format as the DS record.

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

* : 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.

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

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.

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

AXFR : Full Zone Transfer (RFC 1035)
Transfer entire zone file from the master name server to secondary name servers.

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.