Internet Assigned Numbers Authority

Concise Binary Object Representation (CBOR) Tags

Last Updated
Available Formats



Plain text

Registry included below


Carsten Bormann, Christian Amsüss
All registration requests must include the template from [RFC8949].
Available Formats

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 Positive 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 [RFC-ietf-cose-rfc8152bis-struct-15]
17 COSE_Mac0 COSE Mac w/o Recipients Object [RFC-ietf-cose-rfc8152bis-struct-15]
18 COSE_Sign1 COSE Single Signer Data Object [RFC-ietf-cose-rfc8152bis-struct-15]
19-20 Unassigned
21 (any) Expected conversion to base64url encoding; see Section [RFC8949]
22 (any) Expected conversion to base64 encoding; see Section [RFC8949]
23 (any) Expected conversion to base16 encoding; see Section Section [RFC8949]
24 byte string Encoded CBOR data item; see Section [RFC8949]
25 unsigned integer reference the nth previously seen string [][Marc_A._Lehmann]
26 array Serialised Perl object with classname and constructor arguments [][Marc_A._Lehmann]
27 array Serialised language-independent object with type name and constructor arguments [][Marc_A._Lehmann]
28 multiple mark value as (potentially) shared [][Marc_A._Lehmann]
29 unsigned integer reference nth marked value [][Marc_A._Lehmann]
30 array Rational number [][Peter_Occil]
31 Undefined (0xf7) Absent value in a CBOR Array [][Sami_Vaarala]
32 text string URI; see Section [RFC8949]
33 text string base64url; see Section [RFC8949]
34 text string base64; see Section [RFC8949]
35 UTF-8 string Regular expression; see Section [RFC7049]
36 text string MIME message; see Section [RFC8949]
37 byte string Binary UUID ([RFC4122] section 4.1.2) [][Lucas_Clemente]
38 array Language-tagged string [][Peter_Occil]
39 multiple Identifier [][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 [][Volker_Mische]
43 byte string YANG bits datatype; see Section 6.7. [draft-ietf-core-yang-cbor]
44 unsigned integer YANG enumeration datatype; see Section 6.6. [draft-ietf-core-yang-cbor]
45 unsigned integer or text string YANG identityref datatype; see Section 6.10. [draft-ietf-core-yang-cbor]
46 unsigned integer or text string or array YANG instance-identifier datatype; see Section 6.13. [draft-ietf-core-yang-cbor]
47 unsigned integer YANG Schema Item iDentifier (sid); see Section 3.2. [draft-ietf-core-yang-cbor]
48-51 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 [RFC-ietf-cose-rfc8152bis-struct-15]
97 COSE_Mac COSE MACed Data Object [RFC-ietf-cose-rfc8152bis-struct-15]
98 COSE_Sign COSE Signed Data Object [RFC-ietf-cose-rfc8152bis-struct-15]
99 Unassigned
100 Unsigned or negative integer Number of days since the epoch date 1970-01-01 [RFC8943]
101-102 Unassigned
103 array Geographic Coordinates [][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 [RFC9090]
113-119 Unassigned
120 multiple Internet of Things Data Point [][Danilo_Vidovic]
121-255 Unassigned
256 multiple mark value as having string references [][Marc_A._Lehmann]
257 byte string Binary MIME message [][Peter_Occil]
258 array Mathematical finite set [][Alfredo_Di_Napoli]
259 map Map datatype with key-value operations (e.g. `.get()/.set()/.delete()`) [][Shane_Holloway]
260 byte string Network Address (IPv4 or IPv6 or MAC Address) (DEPRECATED in favor of 52 and 54 for IP addresses) [][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) [][Ravi_Raju][RFC9164]
262 byte string Embedded JSON Object [][Ravi_Raju]
263 byte string Hexadecimal string [][Ravi_Raju]
264 array Decimal fraction with arbitrary exponent [][Peter_Occil]
265 array Bigfloat with arbitrary exponent [][Peter_Occil]
266 text string Internationalized resource identifier (IRI) [][Peter_Occil]
267 text string Internationalized resource identifier reference (IRI reference) [][Peter_Occil]
268 array Extended decimal fraction [][Peter_Occil]
269 array Extended bigfloat [][Peter_Occil]
270 array Extended rational number [][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 [][Sami_Vaarala]
273 byte string Non-UTF-8 WTF-8 string [][Sami_Vaarala]
274 byte string Non-UTF-8 MUTF-8 string [][Sami_Vaarala]
275 map (major type 5) Map contains only keys that are of type Text String (major type 3) [][Emile_Cormier]
276 byte string ERIS binary read capability []
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 extended time [draft-bormann-cbor-time-tag-01]
1002 map duration [draft-bormann-cbor-time-tag-01]
1003 map period [draft-bormann-cbor-time-tag-01]
1004 UTF-8 text string [RFC3339] full-date string [RFC8943]
1005-1039 Unassigned
1040 array of two arrays [1] Multi-dimensional Array, column-major order [RFC8746]
1041-22097 Unassigned
22098 multiple hint that indicates an additional level of indirection [][Marc_A._Lehmann]
22099-25440 Unassigned
25441 Array containing at most one array followed by at most one map Capture [3] [][Geoffrey_Broadwell]
25442-49999 Unassigned
50000 integer PlatformV_IS_ID [][Wang_Tongzhou]
50001 text string PlatformV_IS_NAME [][Wang_Tongzhou]
50002 any PlatformV_IS_VALUE [][Wang_Tongzhou]
50003 array PlatformV_HAS_COMPOSITE_VALUE [][Wang_Tongzhou]
50004 array PlatformV_HAS_MAPPED_VALUE [][Wang_Tongzhou]
50005 array PlatformV_HAS_OBJ_ID [][Wang_Tongzhou]
50006 array PlatformV_HAS_OBJ_TAG [][Wang_Tongzhou]
50007 array PlatformV_HAS_CHILD [][Wang_Tongzhou]
50008 array PlatformV_HAS_PROPERTY [][Wang_Tongzhou]
50009 array PlatformV_HAS_META [][Wang_Tongzhou]
50010 array PlatformV_HAS_EVENT [][Wang_Tongzhou]
50011 array PlatformV_HAS_ACTION [][Wang_Tongzhou]
50012-55798 Unassigned
55799 (any) Self-described CBOR; see Section 3.4.6 [RFC8949]
55800 byte-string indicates that the file contains one or more CBOR Sequences [draft-ietf-cbor-file-magic-00][Michael_Richardson_2]
55801-65534 Unassigned
65535 (none valid) always invalid [draft-bormann-cbor-notable-tags-02, Section 10.1]
65536-1330664269 Unassigned
1330664270 byte-string A CBOR encoded Openswan configuration file, as stored on disk for unit test cases. [Michael_Richardson][Samir_Hussain] template/1330664270
1330664271-15309735 Unassigned
15309736 map (major type 5) RAINS Message [][Brian_Trammell]
15309737-4294967294 Unassigned
4294967295 (none valid) always invalid [draft-bormann-cbor-notable-tags-02, Section 10.1]
4294967296 map Intel FPGA SPDM Manifest [Andrew_Draper] template/4294967296
4294967297-18446744073709551614 Unassigned
18446744073709551615 (none valid) always invalid [draft-bormann-cbor-notable-tags-02, Section 10.1]

Contact Information

ID Name Contact URI Last Updated
[Alfredo_Di_Napoli] Alfredo Di Napoli mailto:alfredo.dinapoli& 2017-08-25
[Andrew_Draper] Andrew Draper mailto:andrew.draper& 2021-12-10
[Brian_Trammell] Brian Trammell mailto:ietf& 2016-08-17
[Danilo_Vidovic] Danilo Vidovic mailto:cbor& 2018-04-17
[Emile_Cormier] Emile Cormier mailto:emile.cormier.jr& 2020-03-30
[Geoffrey_Broadwell] Geoffrey Broadwell mailto:gjb& 2021-11-09
[Lucas_Clemente] Lucas Clemente mailto:lucas& 2014-07-01
[Marc_A._Lehmann] Marc A. Lehmann mailto:cbor& 2013-11-26
[Mathew_Meins] Mathew Meins mailto:mm& 2021-02-01
[Michael_B._Jones] Michael B. Jones mailto:mbj& 2018-05-04
[Michael_Richardson] Michael Richardson mailto:mcr& 2021-01-25
[Michael_Richardson_2] Michael Richardson mailto:mcr+ietf& 2021-03-08
[Peter_Occil] Peter Occil mailto:poccil14& 2018-11-09
[Ravi_Raju] Ravi Raju mailto:ravir& 2018-03-06
[Sami_Vaarala] Sami Vaarala mailto:sami.vaarala& 2020-03-18
[Samir_Hussain] Samir Hussain mailto:shussain& 2021-01-25
[Shane_Holloway] Shane Holloway mailto:shane.holloway& 2018-10-25
[Volker_Mische] Volker Mische mailto:volker& 2019-08-23
[Wang_Tongzhou] Wang Tongzhou 2021-02-03


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