Internet Assigned Numbers Authority

Concise Binary Object Representation (CBOR) Tags

Created
2013-09-19
Last Updated
2023-11-17
Available Formats

XML
HTML
Plain text

Registries included below

CBOR Tags

Expert(s)
Carsten Bormann, Christian Amsüss
Reference
[RFC8949]
Note
All registration requests must include the template from [RFC8949].
Available Formats

CSV
Range Registration Procedures
0-23 Standards Action
24-32767 Specification Required
32768-18446744073709551615 First Come First Served
Tag Data Item Semantics Reference Template
0 text string Standard date/time string; see Section 3.4.1 [RFC8949]
1 integer or float Epoch-based date/time; see Section 3.4.2 [RFC8949]
2 byte string Unsigned bignum; see Section 3.4.3 [RFC8949]
3 byte string Negative bignum; see Section 3.4.3 [RFC8949]
4 array Decimal fraction; see Section 3.4.4 [RFC8949]
5 array Bigfloat; see Section 3.4.4 [RFC8949]
6-15 Unassigned
16 COSE_Encrypt0 COSE Single Recipient Encrypted Data Object [RFC9052]
17 COSE_Mac0 COSE Mac w/o Recipients Object [RFC9052]
18 COSE_Sign1 COSE Single Signer Data Object [RFC9052]
19 COSE_Countersignature COSE standalone V2 countersignature [RFC9338]
20 Unassigned
21 (any) Expected conversion to base64url encoding; see Section 3.4.5.2 [RFC8949]
22 (any) Expected conversion to base64 encoding; see Section 3.4.5.2 [RFC8949]
23 (any) Expected conversion to base16 encoding; see Section 3.4.5.2 [RFC8949]
24 byte string Encoded CBOR data item; see Section 3.4.5.1 [RFC8949]
25 unsigned integer reference the nth previously seen string [http://cbor.schmorp.de/stringref][Marc_A._Lehmann]
26 array Serialised Perl object with classname and constructor arguments [http://cbor.schmorp.de/perl-object][Marc_A._Lehmann]
27 array Serialised language-independent object with type name and constructor arguments [http://cbor.schmorp.de/generic-object][Marc_A._Lehmann]
28 multiple mark value as (potentially) shared [http://cbor.schmorp.de/value-sharing][Marc_A._Lehmann]
29 unsigned integer reference nth marked value [http://cbor.schmorp.de/value-sharing][Marc_A._Lehmann]
30 array Rational number [http://peteroupc.github.io/CBOR/rational.html][Peter_Occil]
31 Undefined (0xf7) Absent value in a CBOR Array [https://github.com/svaarala/cbor-specs/blob/master/cbor-absent-tag.rst][Sami_Vaarala]
32 text string URI; see Section 3.4.5.3 [RFC8949]
33 text string base64url; see Section 3.4.5.3 [RFC8949]
34 text string base64; see Section 3.4.5.3 [RFC8949]
35 UTF-8 string Regular expression; see Section 2.4.4.3 [RFC7049]
36 text string MIME message; see Section 3.4.5.3 [RFC8949]
37 byte string Binary UUID ([RFC-ietf-uuidrev-rfc4122bis-14, Section 4]) [https://github.com/lucas-clemente/cbor-specs/blob/master/uuid.md][Lucas_Clemente]
38 array Language-tagged string [RFC9290, Appendix A]
39 multiple Identifier [https://github.com/lucas-clemente/cbor-specs/blob/master/id.md][Lucas_Clemente]
40 array of two arrays [1] Multi-dimensional Array, row-major order [RFC8746]
41 array Homogeneous Array [RFC8746]
42 byte string IPLD content identifier [https://github.com/ipld/cid-cbor/][Volker_Mische]
43 text string YANG bits datatype; see Section 6.7. [RFC9254]
44 text string YANG enumeration datatype; see Section 6.6. [RFC9254]
45 unsigned integer or text string YANG identityref datatype; see Section 6.10. [RFC9254]
46 unsigned integer or text string or array YANG instance-identifier datatype; see Section 6.13. [RFC9254]
47 unsigned integer YANG Schema Item iDentifier (sid); see Section 3.2. [RFC9254]
48 byte string IEEE MAC Address [RFC-ietf-intarea-rfc7042bis-11]
49-51 Unassigned
52 byte string or array IPv4, [prefixlen,IPv4], [IPv4,prefixpart] [RFC9164]
53 Unassigned
54 byte string or array IPv6, [prefixlen,IPv6], [IPv6,prefixpart] [RFC9164]
55-60 Unassigned
61 CBOR Web Token (CWT) CBOR Web Token (CWT) [RFC8392][Michael_B._Jones]
62 Unassigned
63 byte string Encoded CBOR Sequence [RFC8742] [draft-bormann-cbor-notable-tags-02, Section 2.1]
64 byte string uint8 Typed Array [RFC8746]
65 byte string uint16, big endian, Typed Array [RFC8746]
66 byte string uint32, big endian, Typed Array [RFC8746]
67 byte string uint64, big endian, Typed Array [RFC8746]
68 byte string uint8 Typed Array, clamped arithmetic [RFC8746]
69 byte string uint16, little endian, Typed Array [RFC8746]
70 byte string uint32, little endian, Typed Array [RFC8746]
71 byte string uint64, little endian, Typed Array [RFC8746]
72 byte string sint8 Typed Array [RFC8746]
73 byte string sint16, big endian, Typed Array [RFC8746]
74 byte string sint32, big endian, Typed Array [RFC8746]
75 byte string sint64, big endian, Typed Array [RFC8746]
76 byte string (reserved) [RFC8746]
77 byte string sint16, little endian, Typed Array [RFC8746]
78 byte string sint32, little endian, Typed Array [RFC8746]
79 byte string sint64, little endian, Typed Array [RFC8746]
80 byte string IEEE 754 binary16, big endian, Typed Array [RFC8746]
81 byte string IEEE 754 binary32, big endian, Typed Array [RFC8746]
82 byte string IEEE 754 binary64, big endian, Typed Array [RFC8746]
83 byte string IEEE 754 binary128, big endian, Typed Array [RFC8746]
84 byte string IEEE 754 binary16, little endian, Typed Array [RFC8746]
85 byte string IEEE 754 binary32, little endian, Typed Array [RFC8746]
86 byte string IEEE 754 binary64, little endian, Typed Array [RFC8746]
87 byte string IEEE 754 binary128, little endian, Typed Array [RFC8746]
88-95 Unassigned
96 COSE_Encrypt COSE Encrypted Data Object [RFC9052]
97 COSE_Mac COSE MACed Data Object [RFC9052]
98 COSE_Sign COSE Signed Data Object [RFC9052]
99 Unassigned
100 Unsigned or negative integer Number of days since the epoch date 1970-01-01 [RFC8943]
101 array [uint, any] alternatives as given by the uint + 128; see Section 9.1 [draft-bormann-cbor-notable-tags-07]
102 Unassigned
103 array Geographic Coordinates [https://github.com/allthingstalk/cbor/blob/master/CBOR-Tag103-Geographic-Coordinates.md][Danilo_Vidovic]
104 multiple Geographic Coordinate Reference System WKT or EPSG number [draft-clarke-cbor-crs]
105-109 Unassigned
110 byte string, array, or map relative object identifier (BER encoding); SDNV [RFC6256] sequence [RFC9090]
111 byte string, array, or map object identifier (BER encoding) [RFC9090]
112 byte string, array, or map object identifier (BER encoding), relative to 1.3.6.1.4.1 [RFC9090]
113-119 Unassigned
120 multiple Internet of Things Data Point [https://github.com/allthingstalk/cbor/blob/master/CBOR-Tag120-Internet-of-Things-Data-Points.md][Danilo_Vidovic]
121-127 any alternatives 0..6, 1+1 encoding; see Section 9.1 [draft-bormann-cbor-notable-tags-07]
128-199 Unassigned
200 multiple Gordian Envelope [draft-mcnally-envelope-05]
201-255 Unassigned
256 multiple mark value as having string references [http://cbor.schmorp.de/stringref][Marc_A._Lehmann]
257 byte string Binary MIME message [http://peteroupc.github.io/CBOR/binarymime.html][Peter_Occil]
258 array Mathematical finite set [https://github.com/input-output-hk/cbor-sets-spec/blob/master/CBOR_SETS.md][Alfredo_Di_Napoli]
259 map Map datatype with key-value operations (e.g. `.get()/.set()/.delete()`) [https://github.com/shanewholloway/js-cbor-codec/blob/master/docs/CBOR-259-spec--explicit-maps.md][Shane_Holloway]
260 byte string Network Address (IPv4 or IPv6 or MAC Address) (DEPRECATED in favor of 52 and 54 for IP addresses) [http://www.employees.org/~ravir/cbor-network.txt][Ravi_Raju][RFC9164]
261 map (IPAddress + Mask Length) Network Address Prefix (IPv4 or IPv6 Address + Mask Length) (DEPRECATED in favor of 52 and 54 for IP addresses) [https://github.com/toravir/CBOR-Tag-Specs/blob/master/networkPrefix.md][Ravi_Raju][RFC9164]
262 byte string Embedded JSON Object [https://github.com/toravir/CBOR-Tag-Specs/blob/master/embeddedJSON.md][Ravi_Raju]
263 byte string Hexadecimal string [https://github.com/toravir/CBOR-Tag-Specs/blob/master/hexString.md][Ravi_Raju]
264 array Decimal fraction with arbitrary exponent [http://peteroupc.github.io/CBOR/bigfrac.html][Peter_Occil]
265 array Bigfloat with arbitrary exponent [http://peteroupc.github.io/CBOR/bigfrac.html][Peter_Occil]
266 text string Internationalized resource identifier (IRI) [https://peteroupc.github.io/CBOR/iri.html][Peter_Occil]
267 text string Internationalized resource identifier reference (IRI reference) [https://peteroupc.github.io/CBOR/iri.html][Peter_Occil]
268 array Extended decimal fraction [https://peteroupc.github.io/CBOR/extended.html][Peter_Occil]
269 array Extended bigfloat [https://peteroupc.github.io/CBOR/extended.html][Peter_Occil]
270 array Extended rational number [https://peteroupc.github.io/CBOR/extended.html][Peter_Occil]
271 DDoS Open Threat Signaling (DOTS) signal channel object DDoS Open Threat Signaling (DOTS) signal channel object, as defined in [RFC9132] [RFC9132]
272 byte string Non-UTF-8 CESU-8 string [https://github.com/svaarala/cbor-specs/blob/master/cbor-nonutf8-string-tags.rst][Sami_Vaarala]
273 byte string Non-UTF-8 WTF-8 string [https://github.com/svaarala/cbor-specs/blob/master/cbor-nonutf8-string-tags.rst][Sami_Vaarala]
274 byte string Non-UTF-8 MUTF-8 string [https://github.com/svaarala/cbor-specs/blob/master/cbor-nonutf8-string-tags.rst][Sami_Vaarala]
275 map (major type 5) Map contains only keys that are of type Text String (major type 3) [https://github.com/ecorm/cbor-tag-text-key-map][Emile_Cormier]
276 byte string ERIS binary read capability [http://purl.org/eris]
277 byte string Universal Geographical Area Description (GAD) shape; see Section 5 [TS 23.032][Mathew_Meins]
278 byte string Universal Geographical Area Description (GAD) description of velocity; see Section 8 [TS 23.032][Mathew_Meins]
279-1000 Unassigned
1001 map [RFC-ietf-cbor-time-tag-12] extended time [RFC-ietf-cbor-time-tag-12]
1002 map [RFC-ietf-cbor-time-tag-12] duration [RFC-ietf-cbor-time-tag-12]
1003 array [RFC-ietf-cbor-time-tag-12] period [RFC-ietf-cbor-time-tag-12]
1004 UTF-8 text string [RFC3339] full-date string [RFC8943]
1005-1009 Unassigned
1010 array: [id: text string, obj: any] Object type identifier [draft-rundgren-cotx-04]
1011-1039 Unassigned
1040 array of two arrays [1] Multi-dimensional Array, column-major order [RFC8746]
1041-1047 Unassigned
1048 byte string IEEE OUI/CID [RFC-ietf-intarea-rfc7042bis-11]
1049-1279 Unassigned
1280-1400 any alternatives 7..127, 1+2 encoding; see Section 9.1 [draft-bormann-cbor-notable-tags-07]
1401-18299 Unassigned
18300-18555 byte string Bare Hash value (COSE algorithm -256 to -1) [draft-bormann-cbor-notable-tags-09, Section 3.1.1]
18556 array [COSE algorithm identifier, Base Hash value] [draft-bormann-cbor-notable-tags-09, Section 3.1.1]
18557-18811 byte string Bare Hash value (COSE algorithm 1 to 255) [draft-bormann-cbor-notable-tags-09, Section 3.1.1]
18812-21064 Unassigned
21065 text string I-Regexp [draft-bormann-cbor-notable-tags-09, Section 2.1][draft-ietf-jsonpath-iregexp-08]
21066 Array[UTF8string, UTF8string?] ECMAScript RegExp [https://262.ecma-international.org/14.0/#sec-regexp-regular-expression-objects] [https://github.com/hildjj/cbor-specs/blob/main/regexp.md][Joe_Hildebrand]
21067-22097 Unassigned
22098 multiple hint that indicates an additional level of indirection [http://cbor.schmorp.de/indirection][Marc_A._Lehmann]
22099-25440 Unassigned
25441 Array containing at most one array followed by at most one map Capture [3] [https://github.com/japhb/cbor-specs/blob/main/capture.md][Geoffrey_Broadwell]
25442-32767 Unassigned
32768 unsigned integer Identifier for a FHIR constant [Stefan_Genchev] template/32768
32769 multiple External reference [https://gitlab.com/Hawk777/cbor-specs/-/blob/main/external-reference.md][Christopher_Head]
32770-42599 Unassigned
42600 map A confidentiality clearance. The key value pairs of the map are defined in ADatP-4774.4 [Aidan_Murdock] template/42600
42601 array A metadata binding. The elements of the array are defined in AdatP-4778.5. The tag is also used as part of the magic number in on-disk detached and encapsulating bindings. [Aidan_Murdock] template/42601
42602 map A collection of NCMS metadata elements. The key value pairs of the map are defined in AdatP-5636.4 [Aidan_Murdock] template/42602
42603-42999 Unassigned
43000 array Single complex number: array elements are real (I) and imaginary (Q) components [Saajan_Chana] template/43000
43001 array Array of complex numbers in interleaved form: complex value k is stored with real (I) part at array index 2k and imaginary (Q) part at index (2k + 1) [Saajan_Chana] template/43001
43002-49999 Unassigned
50000 integer PlatformV_IS_ID [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50001 text string PlatformV_IS_NAME [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50002 any PlatformV_IS_VALUE [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50003 array PlatformV_HAS_COMPOSITE_VALUE [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50004 array PlatformV_HAS_MAPPED_VALUE [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50005 array PlatformV_HAS_OBJ_ID [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50006 array PlatformV_HAS_OBJ_TAG [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50007 array PlatformV_HAS_CHILD [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50008 array PlatformV_HAS_PROPERTY [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50009 array PlatformV_HAS_META [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50010 array PlatformV_HAS_EVENT [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50011 array PlatformV_HAS_ACTION [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50012 integer PlatformV_IS_TYPE [https://github.com/arthurwangtz/platformv-cbor][Wang_Tongzhou]
50013-55798 Unassigned
55799 (any) Self-described CBOR; see Section 3.4.6 [RFC8949]
55800 tagged byte string indicates that the file contains CBOR Sequences [RFC9277]
55801 tagged byte string indicates that the file starts with a CBOR-Labeled Non-CBOR Data label. [RFC9277]
55802-56499 Unassigned
56500 array (major type 4) Compressed byte string [https://github.com/dectris/documentation/blob/main/cbor/dectris-compression-tag.md][Kal_Conley]
56501-57341 Unassigned
57342 array Identify and define a set of record structures (each a sequence of property names) that can be referenced as tags in the included value (and the scope for the record tag definitions) [https://github.com/kriszyp/cbor-records][Kris_Zyp]
57343 array Identify and define a record structure (a sequence of property names), and use that record structure definition to interpret the included values. [https://github.com/kriszyp/cbor-records][Kris_Zyp]
57344-57599 array References a defined record structure, using that referenced record definition to interpret the included values. [https://github.com/kriszyp/cbor-records][Kris_Zyp]
57600-59999 Unassigned
60000 array The tagged CBOR array contains attestation evidence data with an Intel TEE quote. [Shanwei_Cen] template/60000
60001 array The tagged CBOR array contains attestation evidence data with an Intel TEE report. [Shanwei_Cen] template/60001
60002 array The tagged CBOR array contains attestation evidence data with an Intel SGX report. [Shanwei_Cen] template/60002
60003-65534 Unassigned
65535 (none valid) always invalid; see Section 10.1 [draft-bormann-cbor-notable-tags-02]
65536-79999 Unassigned
80000-80099 byte string, array or map Private tags as suggested in [https://mailarchive.ietf.org/arch/msg/cbor/NJlskB63pjXFt5a6S37tiwJBbCM]. [Tony_Putman] template/80000-80099
80100-15309735 Unassigned
15309736 map (major type 5) RAINS Message [https://britram.github.io/rains-prototype][Brian_Trammell]
15309737-1330664269 Unassigned
1330664270 byte-string A CBOR encoded Openswan configuration file, as stored on disk for unit test cases. [Michael_Richardson][Samir_Hussain] template/1330664270
1330664271-1398229315 Unassigned
1398229316 map Concise Software Identifier (CoSWID) [RFC9393]
1398229317-1668546816 Unassigned
1668546817-1668612095 byte string or any CBOR data item (see Appendix B of [RFC9277]) the representation of content-format ct < 65025 is indicated by tag number TN(ct) = 0x63740101 + (ct / 255) * 256 + ct % 255 [RFC9277]
1668612096-1701996914 Unassigned
1701996915 array Array of content-addressed blocks and ERIS read capabilities [Endo_Renberg] template/1701996915
1701996916 array ERIS-FS image header [Endo_Renberg] template/1701996916
1701996917-4294967294 Unassigned
4294967295 (none valid) always invalid; see Section 10.1 [draft-bormann-cbor-notable-tags-02]
4294967296 map Intel FPGA SPDM Manifest [Andrew_Draper] template/4294967296
4294967297-18446744073709551614 Unassigned
18446744073709551615 (none valid) always invalid; Section 10.1 [draft-bormann-cbor-notable-tags-02]

Timescales

Registration Procedure(s)
RFC and Expert Review Required
Reference
[RFC-ietf-cbor-time-tag-12]
Available Formats

CSV
Timescale Value Semantics Reference
UTC 0 UTC with POSIX Epoch [RFC-ietf-cbor-time-tag-12]
TAI 1 TAI with PTP Epoch [RFC-ietf-cbor-time-tag-12]
Unassigned 2-18446744073709551615

Time Tag Map Keys

Registration Procedure(s)
Specification Required
Expert(s)
Unassigned
Reference
[RFC-ietf-cbor-time-tag-12]
Available Formats

CSV
Value Semantics Reference
-18446744073709551616..-19 Unassigned
-18 attoseconds [RFC-ietf-cbor-time-tag-12]
-15 femtoseconds [RFC-ietf-cbor-time-tag-12]
-12 picoseconds [RFC-ietf-cbor-time-tag-12]
-11 IXDTF Suffix Information (elective) [RFC-ietf-cbor-time-tag-12][draft-ietf-sedate-datetime-extended-11]
-10 IXDTF Time Zone Hint (elective) [RFC-ietf-cbor-time-tag-12][draft-ietf-sedate-datetime-extended-11]
-9 nanoseconds [RFC-ietf-cbor-time-tag-12]
-8 Guarantee [RFC-ietf-cbor-time-tag-12]
-7 Uncertainty [RFC-ietf-cbor-time-tag-12]
-6 microseconds [RFC-ietf-cbor-time-tag-12]
-5 Offset-Scaled Log Variance [RFC-ietf-cbor-time-tag-12]
-4 Clock Accuracy [RFC-ietf-cbor-time-tag-12]
-3 milliseconds [RFC-ietf-cbor-time-tag-12]
-2 Clock Class [RFC-ietf-cbor-time-tag-12]
1 base time value as in CBOR Tag 1 [RFC8949][RFC-ietf-cbor-time-tag-12]
4 base time value as in CBOR Tag 4 [RFC8949][RFC-ietf-cbor-time-tag-12]
5 base time value as in CBOR Tag 5 [RFC8949][RFC-ietf-cbor-time-tag-12]
10 IXDTF Time Zone Hint (critical) [RFC-ietf-cbor-time-tag-12][draft-ietf-sedate-datetime-extended-11]
11 IXDTF Suffix Information (critical) [RFC-ietf-cbor-time-tag-12][draft-ietf-sedate-datetime-extended-11]
12-18446744073709551615 Unassigned

Contact Information

ID Name Contact URI Last Updated
[Aidan_Murdock] Aidan Murdock mailto:aidan.murdock&ncia.nato.int 2022-05-24
[Alfredo_Di_Napoli] Alfredo Di Napoli mailto:alfredo.dinapoli&iohk.io 2017-08-25
[Andrew_Draper] Andrew Draper mailto:andrew.draper&intel.com 2021-12-10
[Brian_Trammell] Brian Trammell mailto:ietf&trammell.ch 2016-08-17
[Christopher_Head] Christopher Head mailto:chead&chead.ca 2022-12-28
[Danilo_Vidovic] Danilo Vidovic mailto:cbor&allthingstalk.com 2018-04-17
[Emile_Cormier] Emile Cormier mailto:emile.cormier.jr&gmail.com 2020-03-30
[Endo_Renberg] Endo Renberg mailto:pukkamustard&posteo.net 2023-07-31
[Geoffrey_Broadwell] Geoffrey Broadwell mailto:gjb&sonic.net 2021-11-09
[Joe_Hildebrand] Joe Hildebrand mailto:joe-ietf&cursive.net 2023-08-04
[Kal_Conley] Kal Conley mailto:kal.conley&dectris.com 2022-08-26
[Kris_Zyp] Kris Zyp mailto:kriszyp&gmail.com 2022-05-23
[Lucas_Clemente] Lucas Clemente mailto:lucas&clemente.io 2014-07-01
[Marc_A._Lehmann] Marc A. Lehmann mailto:cbor&schmorp.de 2013-11-26
[Mathew_Meins] Mathew Meins mailto:mm&blackhelicopters.net 2021-02-01
[Michael_B._Jones] Michael B. Jones mailto:mbj&microsoft.com 2018-05-04
[Michael_Richardson] Michael Richardson mailto:mcr&xelerance.com 2021-01-25
[Peter_Occil] Peter Occil mailto:poccil14&gmail.com 2018-11-09
[Ravi_Raju] Ravi Raju mailto:ravir&employees.org 2018-03-06
[Saajan_Chana] Saajan Chana mailto:saajan.chana&cambridgeconsultants.com 2022-07-20
[Sami_Vaarala] Sami Vaarala mailto:sami.vaarala&iki.fi 2020-03-18
[Samir_Hussain] Samir Hussain mailto:shussain&xelerance.com 2021-01-25
[Shane_Holloway] Shane Holloway mailto:shane.holloway&ieee.org 2018-10-25
[Shanwei_Cen] Shanwei Cen mailto:shanwei.cen&intel.com 2023-01-12
[Stefan_Genchev] Stefan Genchev mailto:stefan.genchev&tum.de 2022-12-09
[Tony_Putman] Tony Putman mailto:anthony.putman&dyson.com 2023-04-26
[Volker_Mische] Volker Mische mailto:volker&protocol.ai 2019-08-23
[Wang_Tongzhou] Wang Tongzhou mailto:tongzhou.wang&siemens.com 2022-10-20

Footnote

[1] 
second element of outer array in data item is native CBOR array 
(major type 4) or Typed Array (one of Tag 64..87)