ISO 24165-2:2021

Digital token identifier (DTI) — Registration, assignment and structure — Part 2: Data elements for registration

This document defines the data elements included in the registry record and used to establish the 1:1 relationship between a digital token and the identifier assigned according to the method in ISO 24165-1.

Jeton digital — Enregistrement, affectation et structure — Partie 2: Données d’enregistrement

General Information

• Status: Published
• Publication Date: 27-Sep-2021
• ICS: 03.060 - Finances. Banking. Monetary systems. Insurance
• Technical Committee: ISO/TC 68/SC 8 - Reference data for financial services
• Drafting Committee: ISO/TC 68/SC 8/WG 3 - Digital Token Identifier – DTI
• Current Stage: 9092 - International Standard to be revised
• Completion Date: 01-Jul-2022

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 24165-2
First edition
2021-09
Digital token identifier (DTI) —
Registration, assignment and
structure —
Part 2:
Data elements for registration
Reference number
ISO 24165-2:2021(E)
© ISO 2021

---------------------- Page: 1 ----------------------
ISO 24165-2:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 24165-2:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Constituents of a registry record . 5
4.1 General . 5
4.2 Classes of information . 5
5 Data elements . 6
5.1 Categories of data elements . 6
5.2 Data elements for base records . 6
5.3 Normative data elements for base records . 6
5.4 Informative data elements . 7
5.5 Data elements for fork record(s) . 8
5.6 Normative data elements for fork record(s) . 9
6 Re gistration Authority . 9
6.1 Name and contact details of the Registration Authority . 9
6.2 S ervice provision for the Registration Authority . 9
Annex A (normative) Data requirements .10
Bibliography .16
iii
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ISO 24165-2:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 68, Financial services, Subcommittee SC
8, Reference data for financial services.
A list of all parts in the ISO 24165 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
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ISO 24165-2:2021(E)
Introduction
With the rise in popularity of peer-to-peer payment systems, relying less on centralized authorities
and instead on aspects of cryptography, decentralized processing and a distributed network for the
maintenance of a shared record of transaction activity, the need to identify the digital tokens issued,
traded, transacted or stored on these networks has grown. Stakeholders in the trading community,
service providers, custodians and regulatory bodies have identified numerous use cases where a
standard identifier for accounting, research, tracking and management of these digital tokens would
improve efficiency and eliminate confusion in the marketplace.
However, the nature of these new types of digital asset means they do not fit within the structure of
existing ISO identifiers, in part because they possibly lack clear reference to an issuing authority and
will therefore not be considered the liability of an issuing authority or corporate governing body. These
digital assets, in many cases, are cross geographic and monetary governance jurisdictions.
Though these digital assets are sometimes referred to as cryptocurrencies, virtual currencies or
digital currencies, the term ‘currency’ has a specific meaning as defined by ISO 4217. This definition
is in conflict with the nature of the digital tokens identified within this document due to the reasons
described above; namely, the lack of monetary authority and geographic location.
Where traditional financial instruments or currencies are tokenized for electronic exchange and issued
by a legal entity including also monetary authority responsible for it, other International Standards,
such as ISO 6166 or ISO 4217, can apply. To eliminate confusion for users of this document, care
has been taken to provide a clear definition and eligibility criteria for assignment of a digital token
identifier (DTI).
This document is addressed to applicants seeking to identify digital tokens conforming to the definition
provided in ISO 24165-1. The data elements described in this document are used to distinguish one set
of digital tokens from another and are, wherever possible, objective and publicly available. Inclusion
in the registry and the issuance of an identifier signifies only the existence of the token and its 1:1
relationship to its identifier.
The ISO 24165 series is organized into the following parts:
— ISO 24165-1 describes the method of registration and assignment of a DTI.
— ISO 24165-2 describes the data elements required for registration and display on the DTI registry.
v
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INTERNATIONAL STANDARD ISO 24165-2:2021(E)
Digital token identifier (DTI) — Registration, assignment
and structure —
Part 2:
Data elements for registration
1 Scope
This document defines the data elements included in the registry record and used to establish the 1:1
relationship between a digital token and the identifier assigned according to the method in ISO 24165-1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10646, Information technology — Universal coded character set (UCS)
ISO 24165-1, Digital token identifier—Registration, assignment and structure—Part 1: Method for
registration and assignment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 24165-1 and the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
auxiliary digital token
non-native digital token created as an application on an existing blockchain or other distributed ledger
technology for its issuance, storage or transaction record
Note 1 to entry: A distributed ledger may support zero or more auxiliary digital tokens.
3.2
auxiliary digital token distributed ledger
assigned digital token identifier of a distributed ledger without a native digital token or with a native
digital token when the distributed ledger is used as the platform for one or more auxiliary digital tokens
(3.1)
EXAMPLE If registering an ERC-20 token operating on the Ethereum blockchain, this data element will
contain the DTI assigned to Ether because Ether is the native digital token on a distributed ledger platform that
supports one or more auxiliary digital tokens.
Note 1 to entry: This indicates the DTI of either the type = 1 or type = 2 digital token identifier type used by the
auxiliary digital token (see 5.3).
1
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ISO 24165-2:2021(E)
3.3
auxiliary digital token mechanism
protocol used to create an auxiliary digital token
EXAMPLE ERC-20 (used for Ethereum) and Omni Layer (used for Bitcoin.)
3.4
auxiliary digital token technical reference
element, such as a smart contract address, used to uniquely identify an auxiliary digital token’s (3.1)
origin on a distributed ledger technology platform
Note 1 to entry: For each auxiliary digital token mechanism (3.3), refer to the specifications of the element,
including the syntax for that element, on the RA website (https:// www .iso .org/ maintenance _agencies .html).
For example, for an auxiliary token mechanism ERC-20, the auxiliary token technical reference would likely be a
smart contract address with a designated syntax.
3.5
block hash
cryptographic hash value of the information contained in a block in a blockchain as specified by the
consensus mechanism
3.6
block hash algorithm
cryptographic hash function, specified by the consensus mechanism of a blockchain, used to produce
the block hash (3.5)
EXAMPLE A double SHA-256 hash (a SHA-256 hash of a SHA-256 hash).
3.7
block header
data structure that includes a cryptographic link to the previous block
Note 1 to entry: A block header can also contain a timestamp, a nonce and other DLT platform-specific data,
including a hash value of corresponding transaction records.
[SOURCE: ISO 22739:2020, 3.4, modified]
3.8
block height
number of blocks preceding a given block in a blockchain
EXAMPLE A genesis block (3.27) has block height = 0.
3.9
consensus mechanism change response
binary choice denoting, if true, that the consensus mechanism used to validate the block at the fork
block height (3.23) identified in the fork record differs from the consensus mechanism used to validate
the block immediately prior to the block at the fork block height identified in the fork record
Note 1 to entry: See 4.1 and 5.3.
3.10
digital token external identifiers type
enumerated list of external identifier (3.18) types for the digital token
3.11
digital token external identifiers value
list of other external identifiers (3.18) for the digital token
2
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ISO 24165-2:2021(E)
3.12
digital token identifier type
categorization of the digital token identifier within the registry
Note 1 to entry: See 5.3.
3.13
digital token long name
string containing the full name of the digital token, as represented in alphanumeric basic Latin
characters
3.14
digital token reference implementation URL
uniform resource locator (URL) pointing to the digital token’s reference implementation or software
repository
Note 1 to entry: The supported set of protocols shall be provided in the RA website https:// www .iso .org/
maintenance _agencies .html.
3.15
digital token short name
short name or ticker symbol used to represent this digital token, as represented in alphanumeric basic
Latin characters
3.16
digital token unit multiplier
multiplier used to map from the unit of value stored on the distributed ledger to the unit of value
associated with the digital token long name (3.13)
EXAMPLE Bitcoin has a digital token unit multiplier of 100,000,000.
3.17
distributed ledger technology type
category of systems implementing distributed ledger technology based on their consensus mechanisms
Note 1 to entry: The applicability of the data elements in base records and fork (3.19) records is dependent on the
combination of digital token identifier type (3.10) and distributed ledger technology type, see 5.3.
3.18
external identifier
identifier, external to this document, that may be used to identify either the digital token or the
underlying asset that this digital token represents
EXAMPLE ISIN (see ISO 6166).
3.19
fork
creation of two or more different versions of a distributed ledger originating from a common starting
point with a single history
Note 1 to entry: A fork might or might not result in the creation of a new digital token.
Note 2 to entry: Terms such as hard fork and soft fork are sometimes used to distinguish backwards compatibility
changes to the consensus mechanism of a blockchain. This document uses the term fork to encompass both
scenarios.
[SOURCE: ISO 22739:2020, 3.45, modified — Notes to entry added.]
3.20
fork block
block having a block height (3.8) equal to the fork block height (3.23) data element specified in a fork
record
3
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ISO 24165-2:2021(E)
3.21
fork block hash
block hash (3.5) of the block with a block height (3.8) equal to the fork block height (3.23)
3.22
fork block hash algorithm
block hash algorithm (3.6) of the fork block (3.20)
Note 1 to entry: The fork block hash algorithm may differ from the genesis block hash algorithm (3.29) when a fork
(3.19) defines a new block hash algorithm as part of a consensus mechanism change
3.23
fork block height
block height (3.8) of the first block after a fork (3.19)
Note 1 to entry: When a digital token is created as a result of a fork, the original blockchain and the new
blockchain are identical for all blocks with a block height less than the fork block height. Blocks on the original
and the new blockchains at the block height equal to or greater than the fork block height will differ.
3.24
fork block UTC timestamp
timestamp, expressed in Coordinated Universal Time, recorded in the fork block (3.20)
Note 1 to entry: Frequently, the fork block UTC timestamp is located in the fork block header.
3.25
functionally fungible
not technically compatible, but considered equivalent
3.26
functionally fungible group
set of digital tokens which are functionally fungible (3.25)
3.27
genesis block
first block in a blockchain
Note 1 to entry: A genesis block has no previous block and serves to initialize the blockchain.
[SOURCE: ISO 22739:2020, 3.37]
3.28
genesis block hash
block hash (3.5) of the genesis block
Note 1 to entry: The genesis block hash is typically recorded in the second block of the blockchain.
3.29
genesis block hash algorithm
block hash algorithm (3.6) used to produce the block hash (3.5) of the genesis block (3.27)
3.30
genesis block UTC timestamp
timestamp, expressed in Coordinated Universal Time, recorded in the genesis block (3.27)
Note 1 to entry: Frequently, the genesis block UTC timestamp is located in the genesis block header (3.7).
3.31
native digital token
digital token with a privileged position in the distributed ledger technology protocol
Note 1 to entry: Also known by the non-standard term protocol token.
4
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ISO 24165-2:2021(E)
3.32
original language digital token long name
string containing the full name of the digital token
3.33
original language digital token short name
short name or ticker symbol used to represent this digital token
3.34
public distributed ledger indicator
binary choice indicating, if true, that access to reading the distributed ledger is unrestricted, and the
data elements specified in this document are accessible for independent verification by the general
public
3.35
underlying asset external identifiers type
enumerated list expressing the types of underlying asset external identifiers (3.18) for the digital token
3.36
underlying
...

INTERNATIONAL ISO
STANDARD 24165-2
First edition
2021-09
Digital token identifier (DTI) —
Registration, assignment and
structure —
Part 2:
Data elements for registration
PROOF/ÉPREUVE
Reference number
ISO 24165-2:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 24165-2:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii PROOF/ÉPREUVE © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 24165-2:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Constituents of a registry record . 5
4.1 General . 5
4.2 Classes of information . 5
5 Data elements . 6
5.1 Categories of data elements . 6
5.2 Data elements for base records . 6
5.3 Normative data elements for base records . 6
5.4 Informative data elements . 7
5.5 Data elements for fork record(s) . 8
5.6 Normative data elements for fork record(s) . 9
6 R egistration Authority . 9
6.1 Name and contact details of the Registration Authority . 9
6.2 Service pr ovision for the Registration Authority . 9
Annex A (normative) Data requirements .10
Bibliography .16
© ISO 2021 – All rights reserved PROOF/ÉPREUVE iii

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ISO 24165-2:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 68, Financial services, Subcommittee SC
8, Reference data for financial services.
A list of all parts in the ISO 24165 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv PROOF/ÉPREUVE © ISO 2021 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 24165-2:2021(E)

Introduction
With the rise in popularity of peer-to-peer payment systems, relying less on centralized authorities
and instead on aspects of cryptography, decentralized processing and a distributed network for the
maintenance of a shared record of transaction activity, the need to identify the digital tokens issued,
traded, transacted or stored on these networks has grown. Stakeholders in the trading community,
service providers, custodians and regulatory bodies have identified numerous use cases where a
standard identifier for accounting, research, tracking and management of these digital tokens would
improve efficiency and eliminate confusion in the marketplace.
However, the nature of these new types of digital asset means they do not fit within the structure of
existing ISO identifiers, in part because they possibly lack clear reference to an issuing authority and
will therefore not be considered the liability of an issuing authority or corporate governing body. These
digital assets, in many cases, are cross geographic and monetary governance jurisdictions.
Though these digital assets are sometimes referred to as cryptocurrencies, virtual currencies or
digital currencies, the term ‘currency’ has a specific meaning as defined by ISO 4217. This definition
is in conflict with the nature of the digital tokens identified within this document due to the reasons
described above; namely, the lack of monetary authority and geographic location.
Where traditional financial instruments or currencies are tokenized for electronic exchange and issued
by a legal entity including also monetary authority responsible for it, other International Standards,
such as ISO 6166 or ISO 4217, can apply. To eliminate confusion for users of this document, care has been
taken to provide a clear definition and eligibility criteria for assignment of a digital token identifier
(DTI).
This document is addressed to applicants seeking to identify digital tokens conforming to the definition
provided in ISO 24165-1. The data elements described in this document are used to distinguish one set
of digital tokens from another and are, wherever possible, objective and publicly available. Inclusion
in the registry and the issuance of an identifier signifies only the existence of the token and its 1:1
relationship to its identifier.
The ISO 24165 series is organized into the following parts:
— ISO 24165-1 describes the method of registration and assignment of a DTI.
— ISO 24165-2 describes the data elements required for registration and display on the DTI registry.
© ISO 2021 – All rights reserved PROOF/ÉPREUVE v

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INTERNATIONAL STANDARD ISO 24165-2:2021(E)
Digital token identifier (DTI) — Registration, assignment
and structure —
Part 2:
Data elements for registration
1 Scope
This document defines the data elements included in the registry record and used to establish the 1:1
relationship between a digital token and the identifier assigned according to the method in ISO 24165-1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 10646, Information technology — Universal coded character set (UCS)
ISO 24165-1, Digital token identifier—Registration, assignment and structure—Part 1: Method for
registration and assignment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 24165-1 and the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
auxiliary digital token
non-native digital token created as an application on an existing blockchain or other distributed ledger
technology for its issuance, storage or transaction record
Note 1 to entry: A distributed ledger may support zero or more auxiliary digital tokens.
3.2
auxiliary digital token distributed ledger
assigned digital token identifier of a distributed ledger without a native digital token or with a native
digital token when the distributed ledger is used as the platform for one or more auxiliary digital tokens
(3.1)
EXAMPLE If registering an ERC-20 token operating on the Ethereum blockchain, this data element will
contain the DTI assigned to Ether because Ether is the native digital token on a distributed ledger platform that
supports one or more auxiliary digital tokens.
Note 1 to entry: This indicates the DTI of either the type = 1 or type = 2 digital token identifier type used by the
auxiliary digital token (see 5.3).
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ISO 24165-2:2021(E)

3.3
auxiliary digital token mechanism
protocol used to create an auxiliary digital token
EXAMPLE ERC-20 (used for Ethereum) and Omni Layer (used for Bitcoin.)
3.4
auxiliary digital token technical reference
element, such as a smart contract address, used to uniquely identify an auxiliary digital token’s (3.1)
origin on a distributed ledger technology platform
Note 1 to entry: For each auxiliary digital token mechanism (3.3), refer to the specifications of the element,
including the syntax for that element, on the RA website (https:// www .iso .org/ maintenance _agencies .html).
For example, for an auxiliary token mechanism ERC-20, the auxiliary token technical reference would likely be a
smart contract address with a designated syntax.
3.5
block hash
cryptographic hash value of the information contained in a block in a blockchain as specified by the
consensus mechanism
3.6
block hash algorithm
cryptographic hash function, specified by the consensus mechanism of a blockchain, used to produce
the block hash (3.5)
EXAMPLE A double SHA-256 hash (a SHA-256 hash of a SHA-256 hash).
3.7
block header
data structure that includes a cryptographic link to the previous block
Note 1 to entry: A block header can also contain a timestamp, a nonce and other DLT platform-specific data,
including a hash value of corresponding transaction records.
[SOURCE: ISO 22739:2020, 3.4, modified]
3.8
block height
number of blocks preceding a given block in a blockchain
EXAMPLE A genesis block (3.27) has block height = 0.
3.9
consensus mechanism change response
binary choice denoting, if true, that the consensus mechanism used to validate the block at the fork
block height (3.23) identified in the fork record differs from the consensus mechanism used to validate
the block immediately prior to the block at the fork block height identified in the fork record
Note 1 to entry: See 4.1 and 5.3.
3.10
digital token external identifiers type
enumerated list of external identifier (3.18) types for the digital token
3.11
digital token external identifiers value
list of other external identifiers (3.18) for the digital token
2 PROOF/ÉPREUVE © ISO 2021 – All rights reserved

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ISO 24165-2:2021(E)

3.12
digital token identifier type
categorization of the digital token identifier within the registry
Note 1 to entry: See 5.3.
3.13
digital token long name
string containing the full name of the digital token, as represented in alphanumeric basic Latin
characters
3.14
digital token reference implementation URL
uniform resource locator (URL) pointing to the digital token’s reference implementation or software
repository
Note 1 to entry: The supported set of protocols shall be provided in the RA website https:// www .iso .org/
maintenance _agencies .html.
3.15
digital token short name
short name or ticker symbol used to represent this digital token, as represented in alphanumeric basic
Latin characters
3.16
digital token unit multiplier
multiplier used to map from the unit of value stored on the distributed ledger to the unit of value
associated with the digital token long name (3.13)
EXAMPLE Bitcoin has a digital token unit multiplier of 100,000,000.
3.17
distributed ledger technology type
category of systems implementing distributed ledger technology based on their consensus mechanisms
Note 1 to entry: The applicability of the data elements in base records and fork (3.19) records is dependent on the
combination of digital token identifier type (3.10) and distributed ledger technology type, see 5.3.
3.18
external identifier
identifier, external to this document, that may be used to identify either the digital token or the
underlying asset that this digital token represents
EXAMPLE ISIN (see ISO 6166).
3.19
fork
creation of two or more different versions of a distributed ledger originating from a common starting
point with a single history
Note 1 to entry: A fork might or might not result in the creation of a new digital token.
Note 2 to entry: Terms such as hard fork and soft fork are sometimes used to distinguish backwards compatibility
changes to the consensus mechanism of a blockchain. This document uses the term fork to encompass both
scenarios.
[SOURCE: ISO 22739:2020, 3.45, modified — Notes to entry added.]
3.20
fork block
block having a block height (3.8) equal to the fork block height (3.23) data element specified in a fork
record
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ISO 24165-2:2021(E)

3.21
fork block hash
block hash (3.5) of the block with a block height (3.8) equal to the fork block height (3.23)
3.22
fork block hash algorithm
block hash algorithm (3.6) of the fork block (3.20)
Note 1 to entry: The fork block hash algorithm may differ from the genesis block hash algorithm (3.29) when a fork
(3.19) defines a new block hash algorithm as part of a consensus mechanism change
3.23
fork block height
block height (3.8) of the first block after a fork (3.19)
Note 1 to entry: When a digital token is created as a result of a fork, the original blockchain and the new
blockchain are identical for all blocks with a block height less than the fork block height. Blocks on the original
and the new blockchains at the block height equal to or greater than the fork block height will differ.
3.24
fork block UTC timestamp
timestamp, expressed in Coordinated Universal Time, recorded in the fork block (3.20)
Note 1 to entry: Frequently, the fork block UTC timestamp is located in the fork block header.
3.25
functionally fungible
not technically compatible, but considered equivalent
3.26
functionally fungible group
set of digital tokens which are functionally fungible (3.25)
3.27
genesis block
first block in a blockchain
Note 1 to entry: A genesis block has no previous block and serves to initialize the blockchain.
[SOURCE: ISO 22739:2020, 3.37]
3.28
genesis block hash
block hash (3.5) of the genesis block
Note 1 to entry: The genesis block hash is typically recorded in the second block of the blockchain.
3.29
genesis block hash algorithm
block hash algorithm (3.6) used to produce the block hash (3.5) of the genesis block (3.27)
3.30
genesis block UTC timestamp
timestamp, expressed in Coordinated Universal Time, recorded in the genesis block (3.27)
Note 1 to entry: Frequently, the genesis block UTC timestamp is located in the genesis block header (3.7).
3.31
native digital token
digital token with a privileged position in the distributed ledger technology protocol
Note 1 to entry: Also known by the non-standard term protocol token.
4 PROOF/ÉPREUVE © ISO 2021 – All rights reserved

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ISO 24165-2:2021(E)

3.32
original language digital token long name
string containing the full name of the digital token
3.33
original language digital token short name
short name or ticker symbol used to represent this digital token
3.34
public distributed ledger indicator
binary choice indicating, if true, that access to reading the distributed ledger is unrestricted, and the
data elements specified in this document are accessible for independent verification by the general
public
3.35
underlying asset external identifiers type
enumerated list expressing the types of underlying asset external identifiers (3.18) for the digital token
3.36
underlying ass
...