Concise Binary Object Representation (CB

Concise Binary Object Representation (CBOR) Tags
Concise Binary Object Representation (CBOR) Tags
Created
2013-09-19
2026-04-02
Available Formats
XML
HTML
Plain text
Registries Included Below
CBOR Tags
Timescales
Time Tag Map Keys
CBOR Tags
Expert(s)
Christian Amsüss, Thomas Fossati, Francesca Palombini, Carsten Bormann (backup)
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
text string
Standard date/time string; see Section 3.4.1
RFC8949
integer or float
Epoch-based date/time; see Section 3.4.2
RFC8949
byte string
Unsigned bignum; see Section 3.4.3
RFC8949
byte string
Negative bignum; see Section 3.4.3
RFC8949
array
Decimal fraction; see Section 3.4.4
RFC8949
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
][
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 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 ([
RFC9562, Section 4
])
][
Lucas_Clemente
38
array
Language-tagged string
RFC9290, Appendix A
39
multiple
Identifier
][
Lucas_Clemente
40
array of two arrays [
Multi-dimensional Array, row-major order
RFC8746
41
array
Homogeneous Array
RFC8746
42
byte string
IPLD content identifier
][
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
RFC9542
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
55-57
Unassigned
58
(any)
An array claim element intended to be redacted, or a map key whose key and value are intended to be redacted. (TEMPORARY - registered 2025-12-09, expires 2026-12-09)
draft-ietf-spice-sd-cwt-06, Section 11.1
59
Unassigned
60
byte string
A selective disclosure redacted (array) claim element. (TEMPORARY - registered 2025-12-09, expires 2026-12-09)
draft-ietf-spice-sd-cwt-06, Section 5.1
61
CBOR Web Token (CWT)
CBOR Web Token (CWT)
RFC8392
][
Michael_B._Jones
62
uint .gt 0
A marker of a location in a map or an array where a decoy is intended to be inserted. (TEMPORARY - registered 2026-01-27, expires 2027-01-27)
draft-ietf-spice-sd-cwt-06, Section 11.2
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
array
CRI Reference
RFC-ietf-core-href-29
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
][
Danilo_Vidovic
104
multiple
Geographic Coordinate Reference System WKT or EPSG number
draft-clarke-cbor-crs-01
105-106
Unassigned
107
map
SUIT_Envelope as defined in Appendix A of [
RFC-ietf-suit-manifest-34
RFC-ietf-suit-manifest-34
108
byte string
Expected conversion to base16 encoding (lowercase)
draft-bormann-cbor-notable-tags-12, Section 2.1, Paragraph 2, Item 2
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
][
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
any
enclosed dCBOR
draft-mcnally-deterministic-cbor-10
202-255
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
array
Coordinate Reference System Wrapper
Fast and Readable Geographical Hashing (CTA-5009-A)
][
Consumer_Technology_Association
280
string or array
Symbol
][
Mihai_Bazon
281
array
Linked list
][
Mihai_Bazon
282
unsigned integer
Character
][
Mihai_Bazon
283
array
Object
][
Mihai_Bazon
284
text string or byte string
JSON Numeric Value, Represented as its JSON Text
][
David_Wheeler
285
array
SUIT_Report_Protected
RFC-ietf-suit-report-19
286
array
SUIT_Reference
RFC-ietf-suit-report-19
287
map
SUIT_Capability_Report
RFC-ietf-suit-report-19
288-295
Unassigned
296
any
isolate shared values within this scope
][
IS4
297-300
Unassigned
301
text string or array
Geohash String
Fast and Readable Geographical Hashing (CTA-5009-A)
][
Consumer_Technology_Association
302-499
Unassigned
500
any
Earmarked for CoRIM
draft-ietf-rats-corim-07
501
map
A CBOR tag that contains a corim-map.
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
502-504
any
Earmarked for CoRIM
draft-ietf-rats-corim-07
505
bytes
A CBOR tag that contains a conciseswid-tag-map.
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
506
bytes
A CBOR tag that contains a concisemid-tag-map.
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
507-525
any
Earmarked for CoRIM
draft-ietf-rats-corim-07
526
map
A CBOR tag that contains an xcorim-map.
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
527
tagged signature block
A CBOR tag that contains either: xcorimmap, or signed-xcorim.
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
528-549
any
Earmarked for CoRIM
draft-ietf-rats-corim-07
550
bytes
A CBOR tag that contains a UEID between 7 and 33 bytes.
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
551
any
Earmarked for CoRIM
draft-ietf-rats-corim-07
552
unsigned integer
A CBOR tag that contains a security version number that is evaluated with equivalence semantics.
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
553
unsigned integer
A CBOR tag that contains min-svn that identifies a security version number that is evaluated with greater than or equals semantics
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
554
string
A CBOR tag that contains a PEM encoded SubjectPublicKeyInfo. See Section 13 of [
RFC7468
].
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
555
string
A CBOR tag that contains a PEM encoded SubjectPublicKeyInfo. See Section 13 of [
RFC7468
].
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
556
string
A CBOR tag that contains an X.509 certificate chain created by the concatenation of as many PEM encoded X.509 certificates as needed. The certificates MUST be concatenated in order that each directly certifies the one preceding.
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
557-559
any
Earmarked for CoRIM
draft-ietf-rats-corim-07
560
bytes
A CBOR tag that contains a byte string interpreted as an array of bits.
TCG DICE Endorsement Architecture for Devices
][
TCG Errata for DICE Endorsement Architecture for Devices Version 1.1
][
TCG
561-569
any
Earmarked for CoRIM
draft-ietf-rats-corim-07
570
map (spdm-toc-map, see CDDL)
spdm-toc-map
TCG DICE Concise Evidence Binding for SPDM
][
TCG
571
map (concise-evidence-map, see CDDL)
concise-evidence-map
TCG DICE Concise Evidence Binding for SPDM
][
TCG
572-599
any
Earmarked for CoRIM
draft-ietf-rats-corim-07
600
Unassigned
601
map (Claims-Set as per Appendix A of [
RFC9781
])
Unprotected CWT Claims Set [
RFC9781
RFC9781
602
array
Detached EAT Bundle
RFC9711, Section 5
603-1000
Unassigned
1001
map
extended time
RFC9581, Section 3
1002
map
duration
RFC9581, Section 4
1003
array
period
RFC9581, Section 5
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 [
Multi-dimensional Array, column-major order
RFC8746
1041-1047
Unassigned
1048
byte string
IEEE OUI/CID
RFC9542
1049-1069
Unassigned
1070
map
SUIT_Manifest as defined in Appendix A of [
RFC-ietf-suit-manifest-34
RFC-ietf-suit-manifest-34
1071-1279
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
18812-20852
Unassigned
20853
any
description of the value instead of the value itself
][
IS4
20854-21064
Unassigned
21065
text string
I-Regexp
draft-bormann-cbor-notable-tags-11, Section 2.1
][
RFC9485
21066
Array[UTF8string, UTF8string?]
ECMAScript RegExp [
][
Joe_Hildebrand
21067-21333
Unassigned
21334
uint
(always invalid in interchange) programming aid for simple values
draft-bormann-cbor-notable-tags-12, Section 10.2
21335-21606
Unassigned
21607
unsigned integer
a CBOR Tag identifier
][
IS4
21608-22097
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
25442-32767
Unassigned
32768
unsigned integer
Identifier for a FHIR constant
Stefan_Genchev
template/32768
32769
multiple
External reference
][
Christopher_Head
32770-32869
unsigned integer
Used to mark pointers in PSA Crypto API IPC implementation
Ole_Saether
template/32770-32869
32870
multiple
Logical operator: NONE / NOT. Encodes the logical operation (!item1&&!item2&&!item3&&..., if array), otherwise (!item).
Jon_Caruana
template/32870
32871
array
Logical operator: ANY. Encodes the logical operation (item1||item2||item3||...).
Jon_Caruana
template/32871
32872
array
Logical operator: ALL. Encodes the logical operation (item1&&item2&&item3&&...).
Jon_Caruana
template/32872
32873-39999
Unassigned
40000
unsigned integer
ur:known-value, Semantic signifier
][
Wolf_McNally
40001
byte string
ur:digest, 32-byte SHA-256 digest
][
Wolf_McNally
40002
array
ur:encrypted, IETF ChaCha20-Poly1305 ([
RFC8439
]) encrypted message
][
Wolf_McNally
40003
array
ur:compressed, [
RFC1951
] DEFLATE-compressed message
][
Wolf_McNally
40004
multiple
ur:request, Transaction Request identifier
][
Wolf_McNally
40005
multiple
ur:response, Transaction response identifier
][
Wolf_McNally
40006
unsigned integer or text string
ur:function, Envelope expression function identifier
][
Wolf_McNally
40007
unsigned integer or text string
ur:parameter, Envelope expression parameter identifier
][
Wolf_McNally
40008
unsigned integer or text string
ur:placeholder, Envelope expression placeholder identifier
][
Wolf_McNally
40009
unsigned integer or text string
ur:replacement, Envelope expression replacement identifier
][
Wolf_McNally
40010
byte string
ur:agreement-private-key, Curve25519 private key for X25519 key agreement
][
Wolf_McNally
40011
byte string
ur:agreement-public-key, Curve25519 public key for X25519 key agreement
][
Wolf_McNally
40012
byte string
ur:arid, Apparently Random Identifier
][
Wolf_McNally
40013
array
ur:crypto-prvkeys, Private keys for cryptographic operations
][
Wolf_McNally
40014
byte string
ur:nonce, Cryptographic nonce
][
Wolf_McNally
40015
array
ur:password, Scrypt-hashed password
][
Wolf_McNally
40016
byte string
ur:crypto-prvkeys, Private key base (key material)
][
Wolf_McNally
40017
array
ur:crypto-pubkeys, Public key base (signing and agreement public key bundle)
][
Wolf_McNally
40018
byte string
ur:salt, Random salt used for hash tree decorrelation
][
Wolf_McNally
40019
array
ur:crypto-sealed, Encrypted message and ephemeral public key
][
Wolf_McNally
40020
multiple
ur:signature, Cryptographic signature
][
Wolf_McNally
40021
byte string
ur:signing-private-key, Cryptographic private key used for signing
][
Wolf_McNally
40022
multiple
ur:signing-public-key, Cryptographic public key used for signing
][
Wolf_McNally
40023
byte string
ur:crypto-key, Cryptographic key used for symmetric encryption
][
Wolf_McNally
40024
multiple
ur:xid, Extensible identifier or XID Document
][
Wolf_McNally
40025
byte string
ur:reference, Cryptographically secure reference to an object
][
Wolf_McNally
40026
unsigned integer or text string
ur:event, Event identifier
][
Wolf_McNally
40027
tagged array
ur:encrypted-key, Content key encrypted with a derivation function
][
Wolf_McNally
40028-40099
Unassigned
40100
array
ur:mlkem-private-key, Private key for MLKEM key encapsulation
][
Wolf_McNally
40101
array
ur:mlkem-public-key, Public key for MLKEM key encapsulation
][
Wolf_McNally
40102
array
ur:mlkem-ciphertext, Ciphertext for MLKEM key encapsulation
][
Wolf_McNally
40103
array
ur:mldsa-private-key, Private key for MLDSA signature generation
][
Wolf_McNally
40104
array
ur:mldsa-public-key, Public key for MLDSA signature verification
][
Wolf_McNally
40105
array
ur:mldsa-signature, MLDSA signature
][
Wolf_McNally
40106-40299
Unassigned
40300
map
ur:seed, Cryptographic seed
][
Wolf_McNally
40301-40302
Unassigned
40303
map
ur:hdkey, Bitcoin BIP-32 HD key
][
Wolf_McNally
40304
map
ur:keypath, Bitcoin BIP-32 key derivation path
][
Wolf_McNally
40305
map
ur:coin-info, Cryptographic asset and network specifier
][
Wolf_McNally
40306
map
ur:eckey, Bitcoin elliptic curve key (private or public)
][
Wolf_McNally
40307
map
ur:address, Cryptocurrency address
][
Wolf_McNally
40308
map
ur:output-descriptor, Bitcoin output descriptor
][
Wolf_McNally
40309
byte string
ur:sskr, Sharded Secret Key Reconstruction (SSKR) share
][
Wolf_McNally
40310
byte string
ur:psbt, Partially Signed Bitcoin Transaction
][
Wolf_McNally
40311
map
ur:account-descriptor, Bitcoin account descriptor
][
Wolf_McNally
40312-40799
Unassigned
40800
text string
ur:ssh-private, Text format SSH private key
][
Wolf_McNally
40801
text string
ur:ssh-public, Text format SSH public key
][
Wolf_McNally
40802
text string
ur:ssh-signature, Text format SSH signature
][
Wolf_McNally
40803
text string
ur:ssh-certificate, Text format SSH certificate
][
Wolf_McNally
40804-40918
Unassigned
40919
multiple (uint or array [uint, uint])
Concordium smart contract address
][
Thomas_Dinsdale-Young
template/40919
40920-41727
Unassigned
41728
array, unsigned integer or unsigned bignum
Fraction
][
Medyro
template/41728
41729
array, unsigned integer or unsigned bignum
Fraction (-NaN signals)
][
Medyro
template/41729
41730
array, unsigned integer or unsigned bignum
Fraction (+NaN signals)
][
Medyro
template/41730
41731
array, unsigned integer or unsigned bignum
Fraction (Both NaNs signal)
][
Medyro
template/41731
41732-42599
Unassigned
42600
map
A confidentiality clearance. The key value pairs of the map are defined in ADatP-4774.8
Aidan_Murdock
template/42600
42601
array
A metadata binding. The elements of the array are defined in AdatP-4778.8.
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-5636.8
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
][
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
integer
PlatformV_IS_TYPE
][
Wang_Tongzhou
50013-51996
Unassigned
51997
array
A tag value of 51997 indicates that the payload is CBOR-LD.
][
Wesley_Smith
template/51997
51998-55798
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
][
Dirk_Boye
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)
][
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.
][
Kris_Zyp
57344-57599
array
References a defined record structure, using that referenced
record definition to interpret the included values.
][
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
60003-60009
Unassigned
60010
array
The tagged CBOR array containing a numeric expression.
][
Ned_Smith
60011-60019
Unassigned
60020
array
The tagged CBOR array containing a set of digests expression.
][
Ned_Smith
60021
array
The tagged CBOR array containing a set of strings expression.
][
Ned_Smith
60022-65534
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 [
].
Tony_Putman
template/80000-80099
80100-80149
byte string, array or map
Private tags as suggested in [
].
Unchained_Infra_Ops
template/80100-80149
80150-80199
byte string, array or map
Private tags as suggested in [
].
Janis_Danisevskis
template/80150-80199
80200-14245119
Unassigned
14245120-14245220
array or map
A tag within this range will indicate that a CBOR-encoded payload
contains a W3C verifiable credential, data integrity proof value. The additional
specificity of the tag in this range is use to identify a particular cryptographic
suite, cryptographic feature, or proof role (base or derived).
Greg_Bernstein
template/14245120-14245220
14245221-15309735
Unassigned
15309736
map (major type 5)
RAINS Message
][
Brian_Trammell
15309737-1146111422
Unassigned
1146111423
map
TCG DICE Protection Environment profile descriptor
TCG DICE Protection Environment
][
TCG
template/1146111423
1146111424-1298360422
Unassigned
1298360423
map
MoaT change-of-status marker
][
Matthias_Urlichs
1298360424-1298493253
Unassigned
1298493254
map
MoaT end-of-file marker
][
Matthias_Urlichs
1298493255-1299145043
Unassigned
1299145044
array
MoaT file identifier / details
][
Matthias_Urlichs
1299145045-1330664269
Unassigned
1330664270
byte-string
A CBOR encoded Openswan configuration file, as stored on disk for
unit test cases.
Michael_Richardson
][
Samir_Hussain
template/1330664270
1330664271-1347571279
Unassigned
1347571280
Proof of Process Packet (PPPP)
A cryptographically anchored data structure used for digital
authorship attestation, capturing the authorship process through entangled
Verifiable Delay Functions (VDFs) and behavioral biometrics.
witnessd Proof of Process Evidence Format, Version 1.3.0
][
David_Lee_Condrey
template/1347571280
1347571281
Compact Evidence Reference
A cryptographic pointer to a full Proof of Process Evidence
Packet, used for embedding authorship claims in space-constrained contexts
(e.g., metadata, QR codes).
witnessd Proof of Process Evidence Format, Version 1.3.0
][
David_Lee_Condrey
template/1347571281
1347571282-1347571541
Unassigned
1347571542
array
ur:provenance, Provenance Mark
][
Wolf_McNally
1347571543-1398229315
Unassigned
1398229316
map
Concise Software Identifier (CoSWID)
RFC9393
1398229317-1413829459
Unassigned
1413829460
any
Explicitly none.
draft-bormann-cbor-notable-tags-15, Section 10.3
][
Joe_Hildebrand
template/1413829460
1413829461-1463894559
Unassigned
1463894560
Writers Authenticity Report (WAR)
An Attestation Result structure produced by Verifiers
appraising Proof of Process Evidence, conveying verification verdicts,
confidence scores, and forensic assessments per the IETF RATS architecture.
witnessd Proof of Process Evidence Format, Version 1.3.0
][
David_Lee_Condrey
template/1463894560
1463894561-1482048303
Unassigned
1482048304-1482048346
integer or map
Xbox Virtual Container identifiers for use with [
RFC 9277
Jon_Caruana
template/1482048304-1482048346
1482048347-1668546816
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
Expert(s)
Henk Birkholz, Esko Dijk
Reference
RFC9581
Available Formats
CSV
Timescale
Value
Semantics
Reference
UTC
UTC with POSIX Epoch
RFC9581
TAI
TAI with PTP Epoch
RFC9581
Unassigned
2-18446744073709551615
Time Tag Map Keys
Registration Procedure(s)
Specification Required
Expert(s)
Henk Birkholz, Esko Dijk
Reference
RFC9581
Available Formats
CSV
Value
Semantics
Reference
-18446744073709551616..-19
Unassigned
-18
attoseconds
RFC9581
-17..-16
Unassigned
-15
femtoseconds
RFC9581
-14
Unassigned
-13
timescale (elective)
RFC9581
-12
picoseconds
RFC9581
-11
IXDTF Suffix Information (elective)
RFC9581
][
RFC9557
-10
IXDTF Time Zone Hint (elective)
RFC9581
][
RFC9557
-9
nanoseconds
RFC9581
-8
Guarantee
RFC9581
-7
Uncertainty
RFC9581
-6
microseconds
RFC9581
-5
Offset-Scaled Log Variance
RFC9581
-4
Clock Accuracy
RFC9581
-3
milliseconds
RFC9581
-2
Clock Class
RFC9581
-1
timescale (elective) legacy
RFC9581
Unassigned
base time value as in CBOR Tag 1
RFC8949
][
RFC9581
2-3
Unassigned
base time value as in CBOR Tag 4
RFC8949
][
RFC9581
base time value as in CBOR Tag 5
RFC8949
][
RFC9581
6-9
Unassigned
10
IXDTF Time Zone Hint (critical)
RFC9581
][
RFC9557
11
IXDTF Suffix Information (critical)
RFC9581
][
RFC9557
12
Unassigned
13
timescale (critical)
RFC9581
14-18446744073709551615
Unassigned
Contact Information
ID
Name
Contact URI
[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
[Consumer_Technology_Association]
Consumer Technology Association
mailto:standards&cta.tech
2024-06-11
[Danilo_Vidovic]
Danilo Vidovic
mailto:cbor&allthingstalk.com
2018-04-17
[David_Lee_Condrey]
David Lee Condrey
mailto:david&writerslogic.com
2026-02-06
[David_Wheeler]
David_Wheeler
mailto:david&justatheory.com
2025-05-16
[Dirk_Boye]
Dirk Boye
mailto:dirk.boye&dectris.com
2024-02-12
[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
[Greg_Bernstein]
Greg Bernstein
mailto:gregb&grotto-networking.com
2024-08-28
[IS4]
IS4
mailto:is4.site&gmail.com
2025-03-06
[Janis_Danisevskis]
Janis Danisevskis
mailto:jdanisevskis&aurora.tech
2025-09-04
[Joe_Hildebrand]
Joe Hildebrand
mailto:joe-ietf&cursive.net
2026-02-11
[Jon_Caruana]
Jon Caruana
mailto:joncar&xbox.com
2025-09-08
[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
[Matthias_Urlichs]
Matthias Urlichs
mailto:matthias&urlichs.de
2025-02-13
[Medyro]
Medyro
mailto:Curious.Charr&web.de
2026-04-02
[Michael_B._Jones]
Michael B. Jones
mailto:mbjµsoft.com
2018-05-04
[Michael_Richardson]
Michael Richardson
mailto:mcr&xelerance.com
2021-01-25
[Mihai_Bazon]
Mihai Bazon
mailto:mihai.bazon&gmail.com
2025-04-03
[Ned_Smith]
Ned Smith
mailto:ned.smith&intel.com
2025-05-12
[Ole_Saether]
Ole Saether
mailto:ole.saether&nordicsemi.no
2024-06-28
[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
[TCG]
Trusted Computing Group
mailto:iana-requests&trustedcomputinggroup.org
2024-03-20
[Thomas_Dinsdale-Young]
Thomas Dinsdale-Young
mailto:ty&concordium.com
2025-08-18
[Tony_Putman]
Tony Putman
mailto:anthony.putman&dyson.com
2023-04-26
[Unchained_Infra_Ops]
Infra Ops
mailto:cbor&unchained.com
2025-09-29
[Volker_Mische]
Volker Mische
mailto:volker.mische&gmail.com
2024-03-05
[Wang_Tongzhou]
Wang Tongzhou
mailto:tongzhou.wang&siemens.com
2022-10-20
[Wesley_Smith]
Wesley Smith
mailto:wsmith&digitalbazaar.com
2025-05-05
[Wolf_McNally]
Wolf McNally
mailto:wolf&wolfmcnally.com
2025-04-28
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)