Internet Assigned Numbers Authority • Domains • Protocols • Numbers • About Domain Name System (DNS) Parameters Last Updated 2026-10-16 Available Formats [IMG] XML [IMG] HTML [IMG] TXT Registries Included Below • DNS CLASSes • Resource Record (RR) TYPEs • DNS OpCodes • DNS RCODEs • AFSDB RR Subtype • DHCID RR Identifier Type Codes • DHCID RR Digest Type Codes • DNS Label Types • DNS EDNS0 Option Codes (OPT) • DNS Header Flags • EDNS Header Flags (16 bits) • EDNS version Number (8 bits) • Child Synchronization (CSYNC) Flags • Underscored and Globally Scoped DNS Node Names • DSO Type Codes • Extended DNS Error Codes • EXTRA-TEXT JSON Names • Contact URI Schemes • Extended DNS Sub-Error Codes • ZONEMD Schemes • ZONEMD Hash Algorithms • DNS Server Cookie Methods • DNS-over-QUIC Error Codes • DNS Catalog Zones Properties • DNS Resolver Information Keys • ZONEVERSION TYPE Values • DSYNC: Location of Synchronization Endpoints DNS CLASSes Expert(s) Petr Špaček, Ladislav Lhotka Reference [RFC 6895][RFC 9108] Note As noted in [RFC 6762], Multicast DNS can only carry DNS records with classes in the range 0-32767. Classes in the range 32768 to 65535 are incompatible with Multicast DNS. Note When this registry is modified, the YANG module [iana-dns-class-rr-type] must be updated as defined in [RFC 9108]. Available Formats [IMG] CSV Decimal Hex Registration Procedures Note 0 0x0000 Standards Action 1-127 0x0000-0x007F IETF Review data CLASSes only 128-253 0x0080-0x00FD IETF Review QCLASSes and meta-CLASSes only 256-32767 0x0100-0x7FFF IETF Review 32768-57343 0x8000-0xDFFF Specification Required data CLASSes only 57344-65279 0xE000-0xFEFF Specification Required QCLASSes and meta-CLASSes only 65280-65534 0xFF00-0xFFFE Private Use 65535 0xFFFF Standards Action Decimal Hexadecimal Name Reference 0 0x0000 Reserved [RFC 6895] 1 0x0001 Internet (IN) [RFC 1035] 2 0x0002 Unassigned 3 0x0003 Chaos (CH) [D. Moon, "Chaosnet", A.I. Memo 628, Massachusetts Institute of Technology Artificial Intelligence Laboratory, June 1981.] 4 0x0004 Hesiod (HS) [Dyer, S., and F. Hsu, "Hesiod", Project Athena Technical Plan - Name Service, April 1987.] 5-253 0x0005-0x00FD Unassigned 254 0x00FE QCLASS NONE [RFC 2136] 255 0x00FF QCLASS * (ANY) [RFC 1035] 256-65279 0x0100-0xFEFF Unassigned 65280-65534 0xFF00-0xFFFE Reserved for Private Use [RFC 6895] 65535 0xFFFF Reserved [RFC 6895] Resource Record (RR) TYPEs Expert(s) Roy Arends, Frederico AC Neves, Ólafur Guðmundsson, Ray Bellis Reference [RFC 6895][RFC 1035][RFC 9108] Note When this registry is modified, the YANG module [iana-dns-class-rr-type] must be updated as defined in [RFC 9108]. Available Formats [IMG] CSV Decimal Hex Registration Procedures Note 0 0x0000 RRTYPE zero is used as a special indicator for the SIG RR [RFC 2931], [RFC 4034] and in other circumstances and must never be allocated for ordinary use. 1-127 0x0000-0x007F Expert Review (see mailing list information in [RFC 6895]) or Standards Action data TYPEs 128-255 0x0080-0x00FF Expert Review (see mailing list information in [RFC 6895]) or Standards Action Q TYPEs, Meta TYPEs 256-61439 0x0100-0xEFFF Expert Review (see mailing list information in [RFC 6895]) or Standards Action data RRTYPEs 61440-65279 0xF000-0xFEFF Reserved for future use (IETF Review required to define use) 65280-65534 0xFF00-0xFFFE Private Use 65535 0xFFFF Reserved (Standards Action) TYPE Value Meaning Reference Template Registration Date Reserved 0 [RFC 6895] 2021-03-08 A 1 a host address [RFC 1035] NS 2 an authoritative [RFC 1035] name server a mail MD 3 destination [RFC 1035] (OBSOLETE - use MX) a mail forwarder MF 4 (OBSOLETE - use [RFC 1035] MX) the canonical CNAME 5 name for an [RFC 1035] alias marks the start SOA 6 of a zone of [RFC 1035] authority a mailbox domain MB 7 name [RFC 1035] (EXPERIMENTAL) a mail group MG 8 member [RFC 1035] (EXPERIMENTAL) a mail rename MR 9 domain name [RFC 1035] (EXPERIMENTAL) NULL 10 a null RR [RFC 1035] (EXPERIMENTAL) a well known WKS 11 service [RFC 1035] description PTR 12 a domain name [RFC 1035] pointer HINFO 13 host information [RFC 1035] MINFO 14 mailbox or mail [RFC 1035] list information MX 15 mail exchange [RFC 1035] TXT 16 text strings [RFC 1035] RP 17 for Responsible [RFC 1183] Person AFSDB 18 for AFS Data [RFC 1183]; [RFC 5864] Base location X25 19 for X.25 PSDN [RFC 1183] address ISDN 20 for ISDN address [RFC 1183] RT 21 for Route [RFC 1183] Through for NSAP NSAP 22 address, NSAP [RFC 1706]; [Moving TPC.INT and NSAP.INT infrastructure style A record domains to historic] (DEPRECATED) for domain name NSAP-PTR 23 pointer, NSAP [RFC 1706]; [Moving TPC.INT and NSAP.INT infrastructure style domains to historic] (DEPRECATED) SIG 24 for security [RFC 2536]; [RFC 2931]; [RFC 3110]; [RFC 4034] signature KEY 25 for security key [RFC 2536]; [RFC 2539]; [RFC 3110]; [RFC 4034] X.400 mail PX 26 mapping [RFC 2163] information GPOS 27 Geographical [RFC 1712] Position AAAA 28 IP6 Address [RFC 3596] LOC 29 Location [RFC 1876] Information NXT 30 Next Domain [RFC 2535]; [RFC 3755] (OBSOLETE) EID 31 Endpoint [Michael_Patton]; 1995-06 Identifier [http://ana-3.lcs.mit.edu/~jnc/nimrod/dns.txt] NIMLOC 32 Nimrod Locator [1][Michael_Patton]; 1995-06 [http://ana-3.lcs.mit.edu/~jnc/nimrod/dns.txt] SRV 33 Server Selection [1][RFC 2782] [ ATM Forum Technical Committee, "ATM Name System, ATMA 34 ATM Address V2.0", Doc ID: AF-DANS-0152.000, July 2000. Available from and held in escrow by IANA.] NAPTR 35 Naming Authority [RFC 3403] Pointer KX 36 Key Exchanger [RFC 2230] CERT 37 CERT [RFC 4398] A6 38 A6 (OBSOLETE - [RFC 2874]; [RFC 3226]; [RFC 6563] use AAAA) DNAME 39 DNAME [RFC 6672] SINK 40 SINK [Donald_E_Eastlake]; [draft-eastlake-kitchen-sink-02] 1997-11 OPT 41 OPT [RFC 3225]; [RFC 6891] APL 42 APL [RFC 3123] DS 43 Delegation [RFC 4034] Signer SSHFP 44 SSH Key [RFC 4255] Fingerprint IPSECKEY 45 IPSECKEY [RFC 4025] RRSIG 46 RRSIG [RFC 4034] NSEC 47 NSEC [RFC 4034]; [RFC 9077] DNSKEY 48 DNSKEY [RFC 4034] DHCID 49 DHCID [RFC 4701] NSEC3 50 NSEC3 [RFC 5155]; [RFC 9077] NSEC3PARAM 51 NSEC3PARAM [RFC 5155] TLSA 52 TLSA [RFC 6698] SMIMEA 53 S/MIME cert [RFC 8162] SMIMEA/smimea-completed-template 2015-12-01 association Extensible Delegation Indirection DELEGPARAM 54 (TEMPORARY - [draft-ietf-deleg-12] 2026-10-16 registered 2026-10-16, expires 2027-10-16) HIP 55 Host Identity [RFC 8005] Protocol NINFO 56 NINFO [Jim_Reid] NINFO/ninfo-completed-template 2008-01-21 RKEY 57 RKEY [Jim_Reid] RKEY/rkey-completed-template 2008-01-21 TALINK 58 Trust Anchor [Wouter_Wijngaards] TALINK/talink-completed-template 2010-02-17 LINK CDS 59 Child DS [RFC 7344] CDS/cds-completed-template 2011-06-06 DNSKEY(s) the CDNSKEY 60 Child wants [RFC 7344] 2014-06-16 reflected in DS OPENPGPKEY 61 OpenPGP Key [RFC 7929] OPENPGPKEY/openpgpkey-completed-template 2014-08-12 CSYNC 62 Child-To-Parent [RFC 7477] 2015-01-27 Synchronization ZONEMD 63 Message Digest [RFC 8976] ZONEMD/zonemd-completed-template 2018-12-12 Over Zone Data SVCB 64 General-purpose [RFC 9460] SVCB/svcb-completed-template 2020-06-30 service binding SVCB-compatible HTTPS 65 type for use [RFC 9460] HTTPS/https-completed-template 2020-06-30 with HTTP Endpoint DSYNC 66 discovery for [RFC 9859] DSYNC/dsync-completed-template 2024-12-10 delegation synchronization Hierarchical HHIT 67 Host Identity [RFC 9886] HHIT/hhit-completed-template 2025-05-20 Tag UAS Broadcast BRID 68 Remote [RFC 9886] BRID/brid-completed-template 2025-05-20 Identification Value coded per UNECE 69 a UNECE [draft-woodcock-faltstrom-external-registry-rrtypes-00] UNECE/unece-completed-template 2026-08-20 Recommendation ISO 70 Value coded per [draft-woodcock-faltstrom-external-registry-rrtypes-00] ISO/iso-completed-template 2026-08-20 an ISO standard Unassigned 71-98 SPF 99 [RFC 7208] UINFO 100 [IANA-Reserved] UID 101 [IANA-Reserved] GID 102 [IANA-Reserved] UNSPEC 103 [IANA-Reserved] NID 104 [RFC 6742] ILNP/nid-completed-template L32 105 [RFC 6742] ILNP/l32-completed-template L64 106 [RFC 6742] ILNP/l64-completed-template LP 107 [RFC 6742] ILNP/lp-completed-template EUI48 108 an EUI-48 [RFC 7043] EUI48/eui48-completed-template 2013-03-27 address EUI64 109 an EUI-64 [RFC 7043] EUI64/eui64-completed-template 2013-03-27 address Unassigned 110-127 NXDOMAIN NXNAME 128 indicator for [RFC 9824] NXNAME/nxname-completed-template 2024-07-18 Compact Denial of Existence Unassigned 129-248 TKEY 249 Transaction Key [RFC 2930] TSIG 250 Transaction [RFC 8945] Signature IXFR 251 incremental [RFC 1995] transfer AXFR 252 transfer of an [RFC 1035]; [RFC 5936] entire zone mailbox-related MAILB 253 RRs (MB, MG or [RFC 1035] MR) mail agent RRs MAILA 254 (OBSOLETE - see [RFC 1035] MX) A request for some or all * 255 records the [RFC 1035]; [RFC 6895]; [RFC 8482] server has available URI 256 URI [RFC 7553] URI/uri-completed-template 2011-02-22 Certification CAA 257 Authority [RFC 8659] CAA/caa-completed-template 2011-04-07 Restriction Application AVC 258 Visibility and [Wolfgang_Riedel] AVC/avc-completed-template 2016-02-26 Control DOA 259 Digital Object [draft-durand-doa-over-dns-02] DOA/doa-completed-template 2017-08-30 Architecture Automatic AMTRELAY 260 Multicast [RFC 8777] AMTRELAY/amtrelay-completed-template 2019-02-06 Tunneling Relay Resolver RESINFO 261 Information as [RFC 9606] RESINFO/resinfo-completed-template 2023-11-02 Key/Value Pairs WALLET 262 Public wallet [Paul_Hoffman] WALLET/wallet-completed-template 2024-06-21 address CLA 263 BP Convergence [draft-johnson-dns-ipn-cla-07] CLA/cla-completed-template 2024-07-25 Layer Adapter IPN 264 BP Node Number [draft-johnson-dns-ipn-cla-07] IPN/ipn-completed-template 2024-07-25 Unassigned 265-32767 DNSSEC Trust [Sam_Weiler]; [ Deploying DNSSEC Without a Signed Root. TA 32768 Authorities Technical Report 1999-19, Information Networking 2005-12-13 Institute, Carnegie Mellon University, April 2004.] DNSSEC Lookaside DLV 32769 Validation [RFC 8749]; [RFC 4431] (OBSOLETE) Unassigned 32770-61439 Extensible Delegation (TEMPORARY - DELEG 61440 registered [draft-ietf-deleg-12] 2026-10-16 2026-10-16, expires 2027-10-16) Unassigned 61441-65279 Private use 65280-65534 Reserved 65535 DNS OpCodes Registration Procedure(s) Standards Action Reference [RFC 6895][RFC 1035] Available Formats [IMG] CSV OpCode Name Reference 0 Query [RFC 1035] 1 IQuery (Inverse Query, OBSOLETE) [RFC 3425] 2 Status [RFC 1035] 3 Unassigned 4 Notify [RFC 1996] 5 Update [RFC 2136] 6 DNS Stateful Operations (DSO) [RFC 8490] 7-15 Unassigned DNS RCODEs Reference [RFC 6895][RFC 1035] Available Formats [IMG] CSV Range Registration Procedures 0-3840 IETF Review 3841-4095 Private Use 4096-65534 IETF Review 65535 Reserved (Standards Action) RCODE Name Description Reference 0 NoError No Error [RFC 1035] 1 FormErr Format Error [RFC 1035] 2 ServFail Server Failure [RFC 1035] 3 NXDomain Non-Existent Domain [RFC 1035] 4 NotImp Not Implemented [RFC 1035] 5 Refused Query Refused [RFC 1035] 6 YXDomain Name Exists when it should not [RFC 2136]; [RFC 6672] 7 YXRRSet RR Set Exists when it should not [RFC 2136] 8 NXRRSet RR Set that should exist does not [RFC 2136] 9 NotAuth Server Not Authoritative for zone [RFC 2136] 9 NotAuth Not Authorized [RFC 8945] 10 NotZone Name not contained in zone [RFC 2136] 11 DSOTYPENI DSO-TYPE Not Implemented [RFC 8490] 12-15 Unassigned 16 BADVERS Bad OPT Version [RFC 6891] 16 BADSIG TSIG Signature Failure [RFC 8945] 17 BADKEY Key not recognized [RFC 8945] 18 BADTIME Signature out of time window [RFC 8945] 19 BADMODE Bad TKEY Mode [RFC 2930] 20 BADNAME Duplicate key name [RFC 2930] 21 BADALG Algorithm not supported [RFC 2930] 22 BADTRUNC Bad Truncation [RFC 8945] 23 BADCOOKIE Bad/missing Server Cookie [RFC 7873] 24-3840 Unassigned 3841-4095 Reserved for Private Use [RFC 6895] 4096-65534 Unassigned 65535 Reserved, can be allocated by Standards Action [RFC 6895] AFSDB RR Subtype Registration Procedure(s) Registry closed per [RFC 6895] Reference [RFC 6895][RFC 1035] Available Formats [IMG] CSV Decimal Hexadecimal Description Reference 0 0x0000 Reserved; registry closed [RFC 6895] 1 0x0001 Andrews File Service v3.0 Location Service [RFC 1183] 2 0x0002 DCE/NCA root cell directory node [RFC 1183] 3-65279 0x0003-0xFEFF Not allocated; registry closed 65280-65534 0xFF00-0xFFFE Reserved for Private Use [RFC 6895] 65535 0xFFFF Reserved; registry closed [RFC 6895] DHCID RR Identifier Type Codes Registration Procedure(s) Standards Action Expert(s) Ólafur Guðmundsson Reference [RFC 4701] Note Registration rules to be as follows: New DHCID RR type codes are tentatively assigned after the specification for the associated type code, published as an Internet Draft, has received expert review by a designated expert. The final assignment of DHCID RR type codes is through Standards Action, as defined in [RFC 2434]. Available Formats [IMG] CSV Identifier Type Code Identifier Reference 0x0000 The 1-octet 'htype' followed by 'hlen' octets of 'chaddr' from a DHCPv4 client's DHCPREQUEST. [RFC 4701] 0x0001 The data octets (i.e., the Type and Client-Identifier fields) from a DHCPv4 client's Client Identifier option. [RFC 4701] 0x0002 The client's DUID (i.e., the data octets of a DHCPv6 client's Client Identifier option or the DUID field from a DHCPv4 [RFC 4701] client's Client Identifier option). 0x0003-0xFFFE Unassigned [RFC 4701] 0xFFFF Reserved [RFC 4701] DHCID RR Digest Type Codes Registration Procedure(s) Standards Action Reference [RFC 4701] Available Formats [IMG] CSV Digest Type Code Description Reference 0 Reserved [RFC 4701] 1 SHA-256 [RFC 4701] 2-255 Unassigned DNS Label Types Registration Procedure(s) Standards Action Reference [RFC 6891] Note The top 2 bits of the first byte of an DNS label indicate the type of label. Available Formats [IMG] CSV Value Type Status Reference 0 0 Normal label lower 6 bits is the length of the label Standard [RFC 1035] 1 1 Compressed label the lower 6 bits and the 8 bits from next octet form a Standard [RFC 1035] pointer to the compression target. 0 1 Extended label type the lower 6 bits of this type (section 3) indicate the Proposed [RFC 6891] type of label in use 0 1 0 0 0 0 0 1 Binary Label Historic [RFC 3364]; [RFC 3363]; [RFC 2673]; [RFC 6891] 0 1 1 1 1 1 1 1 Reserved for future expansion. Proposed [RFC 6891] 1 0 Unallocated DNS EDNS0 Option Codes (OPT) Expert(s) Ólafur Guðmundsson (primary), Frederico AC Neves (secondary), Ray Bellis (secondary), Roy Arends (secondary) Reference [RFC 6891][RFC Errata 3604] Note Registrations made by standards-track documents are listed as "Standard," and by non-standards-track documents as "Optional." Registrations for which there are no final specifications are listed as "On-Hold." Available Formats [IMG] CSV Range Registration Procedures 1-65000 Expert Review 65001-65534 Local/Experimental Use Value Name Status Reference 0 Reserved [RFC 6891] 1 LLQ Optional [RFC 8764] 2 Update Lease Standard [RFC 9664] 3 NSID Standard [RFC 5001] 4 Reserved [draft-cheshire-edns0-owner-option-00] 5 DAU Standard [RFC 6975] 6 DHU Standard [RFC 6975] 7 N3U Standard [RFC 6975] 8 edns-client-subnet Optional [RFC 7871] 9 EDNS EXPIRE Optional [RFC 7314] 10 COOKIE Standard [RFC 7873] 11 edns-tcp-keepalive Standard [RFC 7828] 12 Padding Standard [RFC 7830] 13 CHAIN Standard [RFC 7901] 14 edns-key-tag Optional [RFC 8145] 15 Extended DNS Error Standard [RFC 8914] 16 EDNS-Client-Tag Optional [draft-bellis-dnsop-edns-tags-01] 17 EDNS-Server-Tag Optional [draft-bellis-dnsop-edns-tags-01] 18 Report-Channel Standard [RFC 9567] 19 ZONEVERSION Standard [RFC 9660] 20 MQTYPE-Query Optional [RFC 10029] 21 MQTYPE-Response Optional [RFC 10029] 22 EDE-EXTRA-TEXT-LANGUAGE Optional [draft-muks-dns-filtering-05] 23 FILTERING-CONTACT Optional [draft-muks-dns-filtering-05] 24 FILTERING-ORGANIZATION Optional [draft-muks-dns-filtering-05] 25 FILTERING-DB Optional [draft-muks-dns-filtering-05] 26 Structured DNS Error Standard [RFC-ietf-dnsop-structured-dns-error-27] 27-20291 Unassigned 20292 Umbrella Ident Optional [https://developer.cisco.com/docs/cloud-security/#!integrating-network-devices/rdata-description]; [Cisco_CIE_DNS_team] 20293-26945 Unassigned 26946 DeviceID Optional [https://developer.cisco.com/docs/cloud-security/#!network-devices-getting-started/response-codes]; [Cisco_CIE_DNS_team] 26947-65000 Unassigned 65001-65534 Reserved for [RFC 6891] Local/Experimental Use 65535 Reserved for future [RFC 6891] expansion DNS Header Flags Registration Procedure(s) Standards Action Reference [RFC 6895][RFC 1035] Note In DNS query header there is a flag field in the second 16 bit word in query from bit 5 through bit 11 ([RFC 1035, Section 4.1.1]) Available Formats [IMG] CSV Bit Flag Description Reference bit 5 AA Authoritative Answer [RFC 1035] bit 6 TC Truncated Response [RFC 1035] bit 7 RD Recursion Desired [RFC 1035] bit 8 RA Recursion Available [RFC 1035] bit 9 Reserved bit 10 AD Authentic Data [RFC 4035]; [RFC 6840]; [RFC Errata 4924] bit 11 CD Checking Disabled [RFC 4035]; [RFC 6840]; [RFC Errata 4927] EDNS Header Flags (16 bits) Registration Procedure(s) Standards Action Reference [RFC 6891] Available Formats [IMG] CSV Bit Flag Description Reference Bit 0 DO DNSSEC answer OK [RFC 4035]; [RFC 3225]; [RFC 6840]; [RFC Errata 4928] Bit 1 CO Compact Answers OK [RFC 9824] Bit 2 DE Delegation Extensions (TEMPORARY - registered 2026-07-20, expires 2027-07-20) [draft-ietf-dnsop-delext-08] Bit 3-15 Reserved EDNS version Number (8 bits) Registration Procedure(s) Standards Action Reference [RFC 6891] Available Formats [IMG] CSV Range Description Reference 0 EDNS version 0 [RFC 6891] 1-255 Unassigned Child Synchronization (CSYNC) Flags Registration Procedure(s) Standards Action Reference [RFC 7477] Available Formats [IMG] CSV Bit Flag Description Reference 0 immediate Immediately process this CSYNC record. [RFC 7477, Section 3] 1 soaminimum Require a SOA serial number greater than the one specified. [RFC 7477, Section 2.1.1.1] 2-15 Unassigned Underscored and Globally Scoped DNS Node Names Registration Procedure(s) Expert Review Expert(s) Frederico A C Neves, Paul Wouters Reference [RFC 8552] Available Formats [IMG] CSV RR Type _NODE NAME Reference * _example [RFC 8552, Section 4.1.4] CDNSKEY _signal [RFC 9615] CDS _signal [RFC 9615] DSYNC _dsync [RFC 9859] HTTPS _https [RFC 9460] NULL _ta-* [2] [RFC 8145] OPENPGPKEY _openpgpkey [RFC 7929] SMIMEA _smimecert [RFC 8162] SRV _dccp [RFC 2782] SRV _http [RFC 4386] SRV _ipv6 [RFC 5026] SRV _ldap [RFC 4386] SRV _ocsp [RFC 4386] SRV _sctp [RFC 2782] SRV _sip [RFC 5509] SRV _stun [RFC 8489, Section 8.1] SRV _stuns [RFC 8489, Section 8.1] SRV _tcp [RFC 2782] SRV _turn [RFC 8656, Section 4.1] SRV _turns [RFC 8656, Section 4.1] SRV _udp [RFC 2782] SRV _xmpp [RFC 3921] SVCB _dns [RFC 9461] TLSA _dane [RFC 7671] TLSA _sctp [RFC 6698] TLSA _tcp [RFC 6698] TLSA _udp [RFC 6698] TXT _x402 [draft-hawkins-x402-dns-discovery-01] TXT _acme-challenge [RFC 8555] TXT _dmarc [RFC 9989] TXT _domainkey [RFC 6376] TXT _er [RFC 9567] TXT _for-sale [RFC 10023] TXT _mta-sts [RFC 8461] TXT _nnu-verification [https://nnu.us/specifications/nnu-domain-verification-1.0.txt] TXT _spf [RFC 7208] TXT _splitdns-challenge [RFC 9704] TXT _sztp [RFC 8572] TXT _tcp [RFC 6763] TXT _tls [RFC 8460] TXT _udp [RFC 6763] TXT _validation-contactemail [https://cabforum.org/wp-content/uploads/CA-Browser-Forum-BR-1.7.4.pdf] TXT _validation-contactphone [https://cabforum.org/wp-content/uploads/CA-Browser-Forum-BR-1.7.4.pdf] TXT _vouch [RFC 5518] URI _acct [RFC 7566]; [RFC Errata 7064] URI _dccp [RFC 4340]; [RFC Errata 7066] URI _email [RFC 6118] URI _ems [RFC 6118] URI _fax [RFC 6118] URI _ft [RFC 6118] URI _h323 [RFC 6118] URI _iax [RFC 6315]; [RFC Errata 7065] URI _ical-access [RFC 6118] URI _ical-sched [RFC 6118] URI _ifax [RFC 6118] URI _im [RFC 6118] URI _mms [RFC 6118] URI _pres [RFC 6118] URI _pstn [RFC 6118] URI _sctp [RFC 4340]; [RFC Errata 7067] URI _sip [RFC 6118] URI _sms [RFC 6118] URI _tcp [RFC 4340]; [RFC Errata 7068] URI _udp [RFC 4340]; [RFC Errata 7068] URI _unifmsg [RFC 6118] URI _vcard [RFC 6118] URI _videomsg [RFC 6118] URI _voice [RFC 6118] URI _voicemsg [RFC 6118] URI _vpim [RFC 6118] URI _web [RFC 6118] URI _xmpp [RFC 6118] DSO Type Codes Expert(s) Ted Lemon, Sara Dickinson, John Dickinson Reference [RFC 8490] Available Formats [IMG] CSV Range Registration Procedures 0x0004-0x003F Standards Action 0x0040-0xF7FF Expert Review 0xF800-0xFBFF Experimental/Local Use 0xFC00-0xFFFF Standards Action Type Name Early Data Status Reference 0x0000 Reserved NO Standards Track [RFC 8490] 0x0001 KeepAlive OK Standards Track [RFC 8490] 0x0002 RetryDelay NO Standards Track [RFC 8490] 0x0003 EncryptionPadding NA Standards Track [RFC 8490] 0x0004-0x003F Unassigned, reserved for DSO session-management TLVs NO 0x0040 SUBSCRIBE OK Standards Track [RFC 8765, Section 6.2] 0x0041 PUSH NO Standards Track [RFC 8765, Section 6.3] 0x0042 UNSUBSCRIBE NO Standards Track [RFC 8765, Section 6.4] 0x0043 RECONFIRM NO Standards Track [RFC 8765, Section 6.5] 0x0044-0xF7FF Unassigned NO 0xF800-0xFBFF Reserved for Experimental/Local Use NO [RFC 8490] 0xFC00-0xFFFF Reserved for future expansion NO Extended DNS Error Codes Reference [RFC 8914] Available Formats [IMG] CSV Range Registration Procedures 0-49151 First Come First Served 49152-65535 Private Use INFO-CODE Purpose Reference 0 Other Error [RFC 8914, Section 4.1] 1 Unsupported DNSKEY Algorithm [RFC 8914, Section 4.2] 2 Unsupported DS Digest Type [RFC 8914, Section 4.3] 3 Stale Answer [RFC 8914, Section 4.4]; [RFC 8767] 4 Forged Answer [RFC 8914, Section 4.5] 5 DNSSEC Indeterminate [RFC 8914, Section 4.6] 6 DNSSEC Bogus [RFC 8914, Section 4.7] 7 Signature Expired [RFC 8914, Section 4.8] 8 Signature Not Yet Valid [RFC 8914, Section 4.9] 9 DNSKEY Missing [RFC 8914, Section 4.10] 10 RRSIGs Missing [RFC 8914, Section 4.11] 11 No Zone Key Bit Set [RFC 8914, Section 4.12] 12 NSEC Missing [RFC 8914, Section 4.13] 13 Cached Error [RFC 8914, Section 4.14] 14 Not Ready [RFC 8914, Section 4.15] 15 Blocked [RFC 8914, Section 4.16] 16 Censored [RFC 8914, Section 4.17] 17 Filtered [RFC 8914, Section 4.18] 18 Prohibited [RFC 8914, Section 4.19] 19 Stale NXDomain Answer [RFC 8914, Section 4.20] 20 Not Authoritative [RFC 8914, Section 4.21] 21 Not Supported [RFC 8914, Section 4.22] 22 No Reachable Authority [RFC 8914, Section 4.23] 23 Network Error [RFC 8914, Section 4.24] 24 Invalid Data [RFC 8914, Section 4.25] 25 Signature Expired before Valid [https://github.com/NLnetLabs/unbound/pull/604#discussion_r802678343]; [Willem_Toorop] 26 Too Early [RFC 9250] 27 Unsupported NSEC3 Iterations Value [RFC 9276] 28 Unable to conform to policy [draft-homburg-dnsop-codcp-00] 29 Synthesized [https://github.com/PowerDNS/pdns/pull/12334]; [Otto_Moerbeek] 30 Invalid Query Type [RFC 9824] 31 Rate Limited [draft-muks-dns-ede-rate-limited-02, Section 2] 32 Over Quota [draft-muks-dns-ede-rate-limited-02, Section 3] 33 Negative Trust Anchor [draft-farrokhi-dnsop-ede-nta-00] 34 New Delegation Only [draft-ietf-deleg-10] 35 Blocked by Upstream DNS Server [RFC-ietf-dnsop-structured-dns-error-27] 36-49151 Unassigned 49152-65535 Reserved for Private Use [RFC 8914, Section 5.2] EXTRA-TEXT JSON Names Registration Procedure(s) IETF Review Reference [RFC-ietf-dnsop-structured-dns-error-27] Available Formats [IMG] CSV JSON Name Field Meaning Description Reference c contact The contact details of the IT/InfoSec team to report misclassified DNS [RFC-ietf-dnsop-structured-dns-error-27, Section 4] filtering j justification UTF-8-encoded [RFC 5198] textual justification for a particular DNS [RFC-ietf-dnsop-structured-dns-error-27, Section 4] filtering s sub-error Integer representing the sub-error code for this DNS filtering case [RFC-ietf-dnsop-structured-dns-error-27, Section 4] o organization UTF-8-encoded human-friendly name of the organization that filtered this [RFC-ietf-dnsop-structured-dns-error-27, Section 4] particular DNS query l language Indicates the language of the "j" and "o" fields as defined in [RFC 5646] [RFC-ietf-dnsop-structured-dns-error-27, Section 4] Contact URI Schemes Registration Procedure(s) IETF Review Reference [RFC-ietf-dnsop-structured-dns-error-27] Available Formats [IMG] CSV Name Meaning Reference tel Telephone Number [RFC 3966] mailto Internet mail [RFC 6068] Extended DNS Sub-Error Codes Registration Procedure(s) IETF Review Reference [RFC-ietf-dnsop-structured-dns-error-27] Available Formats [IMG] CSV Number Meaning EDE Codes Applicability Reference 0 Reserved Not used [RFC-ietf-dnsop-structured-dns-error-27, Section 6.1] 1 Malware "Blocked", "Blocked by Upstream DNS Server", "Filtered" [RFC 5901, Section 5.5] 2 Phishing "Blocked", "Blocked by Upstream DNS Server", "Filtered" [RFC 5901, Section 5.5] 3 Spam "Blocked", "Blocked by Upstream DNS Server", "Filtered" [RFC 4949] 4 Spyware "Blocked", "Blocked by Upstream DNS Server", "Filtered" [RFC 4949] 5 Network operator policy "Blocked" [RFC-ietf-dnsop-structured-dns-error-27, Section 6.2] 6 DNS operator policy "Blocked" [RFC-ietf-dnsop-structured-dns-error-27, Section 6.3] 7-255 Unassigned ZONEMD Schemes Expert(s) Warren Kumari, Duane Wessels, Wes Hardaker Reference [RFC 8976] Available Formats [IMG] CSV Range Registration Procedures 1-239 Specification Required 240-254 Private Use Value Description Mnemonic Reference 0 Reserved [RFC 8976] 1 Simple ZONEMD collation SIMPLE [RFC 8976] 2-239 Unassigned 240-254 Reserved for Private Use N/A [RFC 8976] 255 Reserved [RFC 8976] ZONEMD Hash Algorithms Expert(s) Warren Kumari, Duane Wessels, Wes Hardaker Reference [RFC 8976] Available Formats [IMG] CSV Range Registration Procedures 1-239 Specification Required 240-254 Private Use Value Description Mnemonic Reference 0 Reserved [RFC 8976] 1 SHA-384 SHA384 [RFC 8976] 2 SHA-512 SHA512 [RFC 8976] 3-239 Unassigned 240-254 Reserved for Private Use N/A [RFC 8976] 255 Reserved [RFC 8976] DNS Server Cookie Methods Expert(s) Ondřej Surý, Donald Eastlake Reference [RFC 9018][RFC 7873] Note A Server Cookie method (construction and pseudorandom algorithm) is determined by the Version in the first byte of the Cookie and by the Cookie size. Server Cookie size is limited to the inclusive range of 8 to 32 bytes. Available Formats [IMG] CSV Range Registration Procedures Version 1-239, Size 8-32 Expert Review Version 240-254, Size 8-32 Private Use Version Size Method Reference 0 8-32 Reserved [RFC 9018] 1 8-15 Unassigned 1 16 SipHash-2-4 [RFC 9018] 1 17-32 Unassigned 2-239 8-32 Unassigned 240-254 8-32 Reserved for Private Use [RFC 9018] 255 8-32 Reserved [RFC 9018] DNS-over-QUIC Error Codes Expert(s) Sara Dickinson, Christian Huitema Reference [RFC 9250] Available Formats [IMG] CSV Range Registration Procedures provisional (greater than 0x3f) Expert Review provisional registration Date field update First Come First Served permanent, 0x00-0x3f Standards Action or IESG Approval permanent, greater than 0x3f Specification Required Value Error Description Status Specification Date Contact 0x0 DOQ_NO_ERROR No error permanent [RFC 9250, Section 4.3] 2022-04-01 [DPRIVE_WG] 0x1 DOQ_INTERNAL_ERROR Implementation error permanent [RFC 9250, Section 4.3] 2022-04-01 [DPRIVE_WG] 0x2 DOQ_PROTOCOL_ERROR Generic protocol violation permanent [RFC 9250, Section 4.3] 2022-04-01 [DPRIVE_WG] 0x3 DOQ_REQUEST_CANCELLED Request cancelled by client permanent [RFC 9250, Section 4.3] 2022-04-01 [DPRIVE_WG] 0x4 DOQ_EXCESSIVE_LOAD Closing a connection for excessive load permanent [RFC 9250, Section 4.3] 2022-04-01 [DPRIVE_WG] 0x5 DOQ_UNSPECIFIED_ERROR No error reason specified permanent [RFC 9250, Section 4.3] 2022-04-01 [DPRIVE_WG] 0xd098ea5e DOQ_ERROR_RESERVED Alternative error code used for tests permanent [RFC 9250, Section 4.3] 2022-04-01 [DPRIVE_WG] DNS Catalog Zones Properties Expert(s) Peter Thomassen, Ondřej Surý, Willem Toorop Reference [RFC 9432] Note This registry applies to Catalog Zones schema version "2" as specified in [RFC 9432]. Available Formats [IMG] CSV Range Registration Procedures property prefix ends in the label "ext" Private Use all other property prefixes Expert Review Property Prefix Description Status Reference zones List of member zones Standards Track [RFC 9432] version Schema version Standards Track [RFC 9432] coo Change of Ownership Standards Track [RFC 9432] group Group Standards Track [RFC 9432] *.ext Custom properties Private Use [RFC 9432] DNS Resolver Information Keys Registration Procedure(s) Specification Required Expert(s) Tirumal Reddy, Mohamed Boucadair, Ben Schwartz Reference [RFC 9606] Available Formats [IMG] CSV Name Description Reference qnamemin The presence of the key name indicates that QNAME minimisation is enabled. [RFC 9606] exterr Lists the set of enabled extended DNS errors. It must be an INFO-CODE decimal value in the [Extended DNS Error Codes] [RFC 9606] registry. infourl Provides a URL that points to unstructured resolver information that is used for troubleshooting. [RFC 9606] deleg The presence of the key indicates that the DELEG protocol is supported. (TEMPORARY - registered 2026-08-24, expires [draft-ietf-deleg-11] 2027-08-24) ZONEVERSION TYPE Values Expert(s) Hugo Salgado, Mauricio Vergara Ereche, Duane Wessels Reference [RFC 9660] Available Formats [IMG] CSV Range Registration Procedures 0-245 Specification Required 246-254 Private Use 255 Reserved ZONEVERSION TYPE Mnemonic Reference 0 SOA-SERIAL [RFC 9660] 1-245 Unassigned 246-254 Reserved for Private Use [RFC 9660] 255 Reserved [RFC 9660] DSYNC: Location of Synchronization Endpoints Registration Procedure(s) Expert Review Expert(s) Johan Stenstam, Peter Thomassen, John Levine Reference [RFC 9859] Available Formats [IMG] CSV RRtype Scheme (Mnemonic) Purpose Reference 0 Null scheme (no-op) [RFC 9859] CDS 1 (NOTIFY) Delegation management [RFC 9859] CSYNC 1 (NOTIFY) Delegation management [RFC 9859] 2-127 Unassigned 128-255 Reserved for Private Use [RFC 9859] Contact Information ID Name Contact URI Last Updated [Cisco_CIE_DNS_team] Cisco CIE DNS team mailto:cie-eng.dns-team&cisco.com 2021-08-31 [Donald_E_Eastlake] Donald E. Eastlake, III mailto:d3e3e3&gmail.com 1997-11 [DPRIVE_WG] DPRIVE working group mailto:dns-privacy&ietf.org 2022-04-01 [Jim_Reid] Jim Reid mailto:jim&telnic.org 2008-01-21 [Michael_Patton] Michael Patton mailto:map&bbn.com 1995-06 [Otto_Moerbeek] Otto Moerbeek mailto:otto.moerbeek&powerdns.com 2023-03-29 [Paul_Hoffman] Paul Hoffman mailto:paul.hoffman&icann.org 2024-07-01 [Sam_Weiler] Sam Weiler mailto:weiler+iana&tislabs.com 2005-12 [Willem_Toorop] Willem Toorop mailto:willem&nlnetlabs.nl 2022-02-11 [Wolfgang_Riedel] Wolfgang Riedel mailto:wolfgang&cisco.com 2016-02-26 [Wouter_Wijngaards] Wouter Wijngaards mailto:wouter&nlnetlabs.nl 2010-02-17 Footnotes [1] In [RFC 1002], two types are defined. It is not clear that these are in use, though if so their assignment does conflict with those above. NB 32 NetBIOS general Name Service NBSTAT 33 NetBIOS NODE STATUS [2] From [RFC 8552, Section 4.1.3]: Under the NULL RR, the entry "`_ta-*`" denotes all node names beginning with the string "`_ta-*`". It does NOT refer to a DNS wildcard specification. Licensing Terms