SIST ISO 26324:2023

Information and documentation -- Digital object identifier system

This document specifies the syntax, description and resolution functional components of the digital object identifier system. It specifies the general principles for the creation, registration and administration of DOI names (where DOI is an initialism for “digital object identifier”).
This document defines the syntax for a DOI name, which is used for the identification of an object of any material form (digital or physical) or an abstraction (such as a textual work) where there is a functional need to distinguish it from other objects.
The DOI name does not replace, nor is it an alternative for, an identifier used in another scheme, such as the schemes defined by ISO/TC 46/SC 9. This document describes how the DOI system can be used in conjunction with another identifier scheme (for example, to provide additional functionality, such as resolution, where this is not already available), and how the character string of that other scheme can be integrated into the DOI system through the DOI metadata record or the DOI syntax or both.
This document does not specify particular technologies to implement the syntax, description and resolution functional components of the digital object identifier system.

Information et documentation -- Système d'identifiant numérique d'objet

Informatika in dokumentacija - Sistem identifikatorjev digitalnega objekta

Ta dokument določa skladnjo, opis in ločljivost funkcionalnih sestavnih delov sistema identifikatorjev digitalnega objekta. Določa splošna načela za oblikovanje, registracijo in upravljanje imen DOI (DOI je kratica za »identifikator digitalnega objekta«).
Ta dokument določa skladnjo imena DOI, ki se uporablja za identifikacijo objekta v kakršni koli materialni (digitalni ali fizični) ali abstraktni obliki (kot je besedilo), kadar obstaja funkcionalna potreba po njenem razločevanju od drugih objektov.
Ime DOI ne nadomešča in ni alternativa za identifikator, ki se uporablja v drugi shemi, kot so sheme iz standarda ISO/TC 46/SC 9. Ta dokument opisuje, kako se sistem DOI lahko uporablja skupaj z drugo identifikacijsko shemo (da se na primer zagotovi dodatna funkcionalnost, kot je ločljivost, kjer še ni na voljo), in kako se lahko niz znakov druge sheme vključi v sistem DOI prek zapisa metapodatkov DOI ali skladnje DOI oziroma obojega.
Ta dokument ne določa posebnih tehnologij za implementacijo skladnje, opisa in ločljivosti funkcionalnih sestavnih delov sistema identifikatorjev digitalnega objekta.

General Information

• Status: Published
• Public Enquiry End Date: 13-Feb-2022
• Publication Date: 29-Nov-2022
• ICS: 01.140.20 - Information sciences
• Technical Committee: IDT - Information, documentation, language and terminology
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 03-Nov-2022
• Due Date: 08-Jan-2023
• Completion Date: 30-Nov-2022
• Ref Project: ISO 26324:2022 - Information and documentation — Digital object identifier system

Relations

• Replaces: SIST ISO 26324:2013 - Information and documentation -- Digital object identifier system
• Effective Date: 01-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ISO 26324:2023
01-januar-2023
Nadomešča:
SIST ISO 26324:2013
Informatika in dokumentacija - Sistem identifikatorjev digitalnega objekta
Information and documentation -- Digital object identifier system
Information et documentation -- Système d'identifiant numérique d'objet
Ta slovenski standard je istoveten z: ISO 26324:2022
ICS:
01.140.20 Informacijske vede Information sciences
SIST ISO 26324:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 26324:2023

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SIST ISO 26324:2023
INTERNATIONAL ISO
STANDARD 26324
Second edition
2022-08
Information and documentation —
Digital object identifier system
Information et documentation — Système d'identifiant numérique
d'objet
Reference number
ISO 26324:2022(E)
© ISO 2022

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SIST ISO 26324:2023
ISO 26324:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
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
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SIST ISO 26324:2023
ISO 26324:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 DOI name . 3
4.1 Syntax . 3
4.1.1 General characteristics . 3
4.1.2 DOI prefix . 4
4.1.3 DOI suffix . 5
4.2 Visual presentation and other representation of DOI names . 5
4.2.1 Screen and print presentation . 5
4.2.2 URI presentation . 5
4.2.3 Other representations . 6
5 Assignment of DOI name . 6
5.1 Principles of assignment . 6
5.2 Granularity . 6
5.3 Description . 7
5.4 Uniqueness . 7
5.5 Persistence . 7
6 Resolution of DOI name . 7
6.1 General . 7
6.2 Functionality . 8
7 DOI metadata . 8
7.1 General . 8
7.2 Functionality . 9
7.3 Registration of DOI metadata . 9
8 Administration of the DOI system .9
Annex A (normative) Relationship between the DOI system and other identifier schemes .10
Annex B (normative) DOI metadata specification.12
Annex C (normative) Administration of the DOI system .14
Annex D (informative) Transition from ISO 26324:2012 to ISO 26324:2022 .16
Bibliography .18
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SIST ISO 26324:2023
ISO 26324:2022(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 46, Information and documentation,
Subcommittee SC 9, Identification and description.
This second edition cancels and replaces the first edition (ISO 26324:2012), which has been technically
revised. The main changes are as follows.
— The requirement that the directory indicator be “10” has been removed.
— The registration authority now has the ability to assign DOI prefixes with a directory indicator
other than “10” (including prefixes consisting of a directory indicator alone), allowing existing
identification schemes with a compatible syntax to request that those schemes become part of the
DOI system.
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.
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SIST ISO 26324:2023
ISO 26324:2022(E)
Introduction
1)
The digital object identifier (DOI® ) system provides an infrastructure for persistent unique
identification of objects of any type.
DOI is an initialism for “digital object identifier”, meaning a “digital identifier of an object” rather than an
“identifier of a digital object”. In this document, the term “digital object identifier” refers to the system
defined in this document, unless otherwise stated. The DOI system was initiated by the International
DOI Foundation in 1998, and initially developed with the collaboration of some participants in
ISO/TC 46/SC 9. Due to its application in the fields of information and documentation and previous
collaboration with some ISO/TC 46/SC 9 participants, it was introduced as a possible work item in 2004
and further developed from 2006 to 2010.
The DOI system offers a useful set of functionalities, including:
— persistence, if material is moved, rearranged, or bookmarked,
— interoperability with other data from other sources,
— extensibility by adding new features and services through management of groups of DOI names,
— single management of data for multiple output formats (platform independence),
— class management of applications and services, and
— dynamic updating of metadata, applications and services.
The DOI system is designed to work over the Internet. A DOI name is permanently assigned to an object
to provide a resolvable persistent network link to current information about that object, including
where the object, or information about it, can be found on the Internet. While information about an
object can change over time, its DOI name will not change. A DOI name can be resolved within the DOI
system to values of one or more types of data relating to the object identified by that DOI name, such as
a URL, an e-mail address, other identifiers and descriptive metadata.
The DOI system enables the construction of automated services and transactions. Applications of
the DOI system include but are not limited to managing information and documentation location and
access; managing metadata; facilitating electronic transactions; persistent unique identification of any
form of any data; and commercial and non-commercial transactions.
The content of an object associated with a DOI name is described unambiguously by DOI metadata,
based on a structured extensible data model that enables the object to be associated with metadata of
any desired degree of precision and granularity to support description and services. The data model
supports interoperability between DOI applications.
The scope of the DOI system is not defined by reference to the type of content (format, etc.) of the
referent, but by reference to the functionalities it provides and the context of use. The DOI system
provides, within networks of DOI applications, for unique identification, persistence, resolution,
metadata and semantic interoperability.
1) DOI® is a registered trademark. The Handbook published by the ISO 26324 Registration Authority (see
Clause 8) contains information on trademark issues. The name and contact information of the ISO 26324 Registration
Authority can be found at https://www.iso.org/maintenance_agencies.html.
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SIST ISO 26324:2023

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SIST ISO 26324:2023
INTERNATIONAL STANDARD ISO 26324:2022(E)
Information and documentation — Digital object identifier
system
1 Scope
This document specifies the syntax, description and resolution functional components of the
digital object identifier system. It specifies the general principles for the creation, registration and
administration of DOI names (where DOI is an initialism for “digital object identifier”).
This document defines the syntax for a DOI name, which is used for the identification of an object of any
material form (digital or physical) or an abstraction (such as a textual work) where there is a functional
need to distinguish it from other objects.
The DOI name does not replace, nor is it an alternative for, an identifier used in another scheme, such
as the schemes defined by ISO/TC 46/SC 9. This document describes how the DOI system can be used
in conjunction with another identifier scheme (for example, to provide additional functionality, such as
resolution, where this is not already available), and how the character string of that other scheme can
be integrated into the DOI system through the DOI metadata record or the DOI syntax or both.
This document does not specify particular technologies to implement the syntax, description and
resolution functional components of the digital object identifier system.
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.
UNICODE CONSORTIUM The Unicode® Standard. Mountain View, California: Unicode Consortium.
Latest edition available at: https:// www .unicode .org/ versions/ latest/
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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 https:// www .electropedia .org/
3.1
DOI system
social and technical infrastructure for the assignment and administration of DOI names (3.2)
as identifiers in computer-readable form through assignment, resolution, referent description,
administration, etc.
3.2
DOI name
string that specifies a unique object (3.3) within the DOI system (3.1)
Note 1 to entry: Names consist of characters in a sequence specified by the DOI syntax (3.4).
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Note 2 to entry: The terms “identifier” and “number” are sometimes but not always used in the same sense and
are to be avoided where ambiguity can arise. The unqualified use of “DOI” alone can also be ambiguous. Therefore
“DOI” is always used in conjunction with a specific noun such as DOI name (3.2) or DOI system (3.1) unless the
meaning is sufficiently clear from an earlier mention or the specific context.
3.3
object
entity within the scope of the DOI system (3.1) that can be digital, physical or abstract
Note 1 to entry: Digital, physical or abstract forms of an entity can be of relevance in information and
documentation (e.g. resources, people or agreements).
Note 2 to entry: A particular object identified by a specific DOI name (3.2) is the referent (3.16) of that DOI name.
3.4
DOI syntax
rules for the form and sequence of characters comprising any DOI name (3.2), specifically the form and
character of a prefix element, separator and suffix element
3.5
directory indicator
unique string allocated to a registrant for the purpose of assignment of DOI names, forming part of the
prefix element of the DOI syntax (3.4) but having no other implied meaning
3.6
registrant code
unique string assigned to a registrant, forming part of the prefix element of the DOI syntax (3.4) but
having no other implied meaning
3.7
DOI metadata
specific data associated with a referent within the DOI system (3.1), based on a structured data model
that enables the referent of the DOI name (3.2) to be associated with data of any desired degree of
precision and granularity to support identification, description and services
Note 1 to entry: DOI metadata is specified in Annex B.
3.8
DOI kernel metadata
subset of DOI metadata (3.7) that is common to all DOI name assignments
Note 1 to entry: DOI kernel metadata is specified in Annex B.
3.9
application profile
set of DOI names (3.2) that share some common characteristics
Note 1 to entry: A DOI application profile is a grouping mechanism for DOI names (3.2); the functional
specification of the application profile includes a set of DOI metadata, comprising the DOI kernel metadata and
additional information applicable to that particular genre of object and functional requirements. Each DOI name
is associated with one or more application profiles.
3.10
data dictionary
repository for all data elements and allowed values (3.11) of those elements used in DOI metadata
specifications
3.11
allowed value
item which may be used as a value of an element
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3.12
opaque string
syntax string that has no meaning discernible by simple inspection
Note 1 to entry: To discover meaning, there is a need to refer to metadata.
3.13
registrant
person or organization that has requested and received the registration of a particular DOI name (3.2)
3.14
interoperability
ability of independent systems to exchange meaningful information and initiate actions from each
other, in order to operate together to mutual benefit
Note 1 to entry: In particular, interoperability constitutes the ability for loosely-coupled independent systems to
be able to collaborate and communicate. See Reference [14] for further information about interoperability.
3.15
resolution
process of submitting a DOI name (3.2) to a network service and receiving in return one or more pieces
of current information related to the identified object such as metadata or a location of the object or of
metadata
Note 1 to entry: This can involve one or more intermediate mapping operations. The resolution might or might
not return an instance of the object. Multiple resolution is the simultaneous return as output of several pieces of
current information related to the object, in defined data structures.
3.16
referent
particular object (3.3) identified by a DOI name (3.2)
3.17
unique identification
specification by a DOI name (3.2) of one and only one referent (3.16)
3.18
persistent
existence, and ability to be used in services outside the direct control of the issuing assigner, without a
stated time limit
3.19
first class
having an identity of itself, not as some attribute of an object
Note 1 to entry: An address is an attribute of something, whereas the thing that has this attribute is a first class
object. A DOI name references an entity as a first-class object, not simply the place where the object is located. It
may then resolve to a location.
4 DOI name
4.1 Syntax
4.1.1 General characteristics
The DOI syntax shall be made up of a DOI prefix and a DOI suffix separated by a forward slash.
There is no defined limit on the length of the DOI name, or of the DOI prefix or DOI suffix.
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SIST ISO 26324:2023
ISO 26324:2022(E)
The DOI name shall be case-insensitive and shall contain only printable characters from the legal
graphic characters specified by the Unicode Standard. Further constraints on character use (e.g. use
of language-specific alphanumeric characters) can be defined for an application by the ISO 26324
Registration Authority.
The combination of a unique DOI prefix (assigned to a particular DOI registrant) and a unique DOI
suffix (provided by that registrant for a specific object) shall be unique. This allows the de-centralized
allocation of DOI names. The registration of the combination of the prefix and suffix in the DOI system
also serves to validate the DOI syntax for a given DOI name.
The DOI name shall be regarded as an opaque string by users of the DOI system. No definitive information
shall be inferred from the specific character string of a DOI name. In particular, the inclusion in a DOI
name of any DOI prefix allocated to a specific registrant does not provide evidence of the ownership
of rights or current management responsibility of any intellectual property in the referent. The mere
assignment of a DOI name to a referent shall not imply endorsement of the referent by any party. Such
information may be asserted in the associated DOI metadata.
4.1.2 DOI prefix
4.1.2.1 Elements
4.1.2.1.1 General
The DOI prefix shall be composed of a directory indicator optionally followed by a registrant code.
Where a registrant code is present, the two components shall be separated by a full stop (period).
The DOI prefix is a unique string allocated to a registrant.
4.1.2.1.2 Directory indicator
The directory indicator shall be allocated, optionally with a registrant code, to a registrant by the
ISO 26324 Registration Authority for the purpose of the assignment of DOI names.
Where a registrant code was allocated to a registrant under a previous edition of this document, the
assignment of “10” as the directory indicator shall be assumed.
Information on the implications of allocating a directory indicator other than “10” is contained in
Annex D.
A user of the DOI system can determine whether a directory indicator is valid for use in DOI names
by consulting the register managed by the ISO 26324 Registration Authority in accordance with the
requirement in C.2.
4.1.2.1.3 Registrant code
Where present, the second element of the DOI prefix shall be the registrant code allocated by the
ISO 26324 Registration Authority. A registrant code shall always be used with the directory indicator
with which it is allocated.
EXAMPLE 1
10.1000 DOI prefix comprising a directory indicator “10” followed by registrant code “1000”.
The registrant code may be further divided into sub-elements for administrative convenience if
desired. Each sub-element of the registrant code shall be preceded by a full stop. Such subdivision
implies no hierarchical relationship; each registrant code, whether subdivided or not, has equal status
in the DOI system. However, a subdivided registrant code can have technical resolution implications. It
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SIST ISO 26324:2023
ISO 26324:2022(E)
is recommended that registrants consult the ISO 26324 Registration Authority for further information
about assignment of registrant codes.
EXAMPLE 2
10.1000.11 DOI prefix in which the registrant code (“1000.11”) has a subdivision “11”.
The registrant code shall be omitted where a directory indicator has been assigned without one.
EXAMPLE 3
15434 DOI prefix consisting of only a directory indicator where no registrant code has been
assigned.
4.1.2.2 Changes
Once a DOI name has been assigned, it shall not be changed regardless of any changes in the ownership
or management of the referent.
NOTE The original registrant might no longer have any role in maintaining a DOI name and its associated
records even though its registrant code remains a permanent element of that DOI name.
4.1.3 DOI suffix
The DOI suffix shall consist of a character string of any length chosen by the registrant. Each suffix
shall be unique to the prefix element that precedes it. The unique suffix can be a sequential number, or
it might incorporate an identifier generated from or based on another system used by the registrant,
[5][6] [3] [2] [10]
such as ISAN , ISRC , ISSN , ISNI ; in such cases, a preferred construction for such a suffix may
be specified by the ISO 26324 Registration Authority as in Example 2. When constructing DOI names
from other identifier systems, including schemes where the DOI prefix is affected, the procedures in
Annex A shall be followed.
EXAMPLE 1
10.1000/123456 DOI name with the DOI prefix “10.1000” and the DOI suffix “123456”.
EXAMPLE 2
10.1038/issn.1476-4687 DOI suffix using an ISSN. According to the construction used here, a DOI suffix
is assembled using an ISSN by preceding the ISSN (including the hyphen) with
the lowercase letters “issn” and a period. This hypothetical example is a DOI
for the electronic version of Nature.
4.2 Visual presentation and other representation of DOI names
4.2.1 Screen and print presentation
When displayed on screen or in print, a DOI name shall be preceded by a lowercase “doi:” unless the
context clearly indicates that a DOI name is implied. The "doi:” label is not part of the DOI name value.
EXAMPLE
The DOI name “10.1006/jmbi.1998.2354” is displayed and printed as "doi: 10 .1006/ jmbi .1998 .2354".
4.2.2 URI presentation
[13]
The use of the lowercase string “doi” complies with the syntax of IETF specification, RFC 3986, for
representation as a URI (uniform resource identifier), such as “ftp:” and “http:”.
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ISO 26324:2022(E)
When displayed in web browsers, the DOI name can be attached to the address for an appropriate
proxy server, to enable resolution of the DOI name via a standard web hyperlink. To resolve a DOI via
a standard web hyperlink, the DOI name itself should be appended to the address for the proxy server.
EXAMPLE
The DOI name “10.1006/jmbi.1998.2354” would be made an actionable link as “https:// doi .org/ 10 .1006/
jmbi .1998 .2354”.
DOI names so represented in a URL and transported by the HTTP protocol are constrained to follow
standard IETF guidelines for URI representations. The syntax for URIs is more restrictive than the
syntax for DOIs; some characters are reserved and will need percent-encoding.
NOTE Certain client or server software might be able to process DOIs using native resolution technology
(i.e. doi: 10 .1006/ jmbi .1998 .2354 would be interpreted by the browser and automatically resolved without the
addition of the proxy server address).
4.2.3 Other representations
DOI names can be represented in other forms in certain contexts.
Characters which cannot be handled directly in a specific network or reference context, or where
ambiguity can arise (e.g. minus sign, the hyphen, and the en-dash all look similar on the screen but
carry different character values) should be avoided or encoded in an appropriate way (e.g. for URLs
convert to UTF-8 and then percent-encode).
5 Assignment of DOI name
5.1 Principles of assignment
[5][6] [1]
A DOI name shall not be used as a replacement for other ISO identifier schemes such as ISAN, ISBN,
[3] [2] [10]
ISRC, ISSN, ISNI and other commonly recognized identifiers. When constructing DOI names from
other identifier systems, including schemes where the DOI prefix is affected, the procedures in Annex A
shal
...

INTERNATIONAL ISO
STANDARD 26324
Second edition
2022-08
Information and documentation —
Digital object identifier system
Information et documentation — Système d'identifiant numérique
d'objet
Reference number
ISO 26324:2022(E)
© ISO 2022

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ISO 26324:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
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 2022 – All rights reserved

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ISO 26324:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 DOI name . 3
4.1 Syntax . 3
4.1.1 General characteristics . 3
4.1.2 DOI prefix . 4
4.1.3 DOI suffix . 5
4.2 Visual presentation and other representation of DOI names . 5
4.2.1 Screen and print presentation . 5
4.2.2 URI presentation . 5
4.2.3 Other representations . 6
5 Assignment of DOI name . 6
5.1 Principles of assignment . 6
5.2 Granularity . 6
5.3 Description . 7
5.4 Uniqueness . 7
5.5 Persistence . 7
6 Resolution of DOI name . 7
6.1 General . 7
6.2 Functionality . 8
7 DOI metadata . 8
7.1 General . 8
7.2 Functionality . 9
7.3 Registration of DOI metadata . 9
8 Administration of the DOI system .9
Annex A (normative) Relationship between the DOI system and other identifier schemes .10
Annex B (normative) DOI metadata specification.12
Annex C (normative) Administration of the DOI system .14
Annex D (informative) Transition from ISO 26324:2012 to ISO 26324:2022 .16
Bibliography .18
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ISO 26324:2022(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 46, Information and documentation,
Subcommittee SC 9, Identification and description.
This second edition cancels and replaces the first edition (ISO 26324:2012), which has been technically
revised. The main changes are as follows.
— The requirement that the directory indicator be “10” has been removed.
— The registration authority now has the ability to assign DOI prefixes with a directory indicator
other than “10” (including prefixes consisting of a directory indicator alone), allowing existing
identification schemes with a compatible syntax to request that those schemes become part of the
DOI system.
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 26324:2022(E)
Introduction
1)
The digital object identifier (DOI® ) system provides an infrastructure for persistent unique
identification of objects of any type.
DOI is an initialism for “digital object identifier”, meaning a “digital identifier of an object” rather than an
“identifier of a digital object”. In this document, the term “digital object identifier” refers to the system
defined in this document, unless otherwise stated. The DOI system was initiated by the International
DOI Foundation in 1998, and initially developed with the collaboration of some participants in
ISO/TC 46/SC 9. Due to its application in the fields of information and documentation and previous
collaboration with some ISO/TC 46/SC 9 participants, it was introduced as a possible work item in 2004
and further developed from 2006 to 2010.
The DOI system offers a useful set of functionalities, including:
— persistence, if material is moved, rearranged, or bookmarked,
— interoperability with other data from other sources,
— extensibility by adding new features and services through management of groups of DOI names,
— single management of data for multiple output formats (platform independence),
— class management of applications and services, and
— dynamic updating of metadata, applications and services.
The DOI system is designed to work over the Internet. A DOI name is permanently assigned to an object
to provide a resolvable persistent network link to current information about that object, including
where the object, or information about it, can be found on the Internet. While information about an
object can change over time, its DOI name will not change. A DOI name can be resolved within the DOI
system to values of one or more types of data relating to the object identified by that DOI name, such as
a URL, an e-mail address, other identifiers and descriptive metadata.
The DOI system enables the construction of automated services and transactions. Applications of
the DOI system include but are not limited to managing information and documentation location and
access; managing metadata; facilitating electronic transactions; persistent unique identification of any
form of any data; and commercial and non-commercial transactions.
The content of an object associated with a DOI name is described unambiguously by DOI metadata,
based on a structured extensible data model that enables the object to be associated with metadata of
any desired degree of precision and granularity to support description and services. The data model
supports interoperability between DOI applications.
The scope of the DOI system is not defined by reference to the type of content (format, etc.) of the
referent, but by reference to the functionalities it provides and the context of use. The DOI system
provides, within networks of DOI applications, for unique identification, persistence, resolution,
metadata and semantic interoperability.
1) DOI® is a registered trademark. The Handbook published by the ISO 26324 Registration Authority (see
Clause 8) contains information on trademark issues. The name and contact information of the ISO 26324 Registration
Authority can be found at https://www.iso.org/maintenance_agencies.html.
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INTERNATIONAL STANDARD ISO 26324:2022(E)
Information and documentation — Digital object identifier
system
1 Scope
This document specifies the syntax, description and resolution functional components of the
digital object identifier system. It specifies the general principles for the creation, registration and
administration of DOI names (where DOI is an initialism for “digital object identifier”).
This document defines the syntax for a DOI name, which is used for the identification of an object of any
material form (digital or physical) or an abstraction (such as a textual work) where there is a functional
need to distinguish it from other objects.
The DOI name does not replace, nor is it an alternative for, an identifier used in another scheme, such
as the schemes defined by ISO/TC 46/SC 9. This document describes how the DOI system can be used
in conjunction with another identifier scheme (for example, to provide additional functionality, such as
resolution, where this is not already available), and how the character string of that other scheme can
be integrated into the DOI system through the DOI metadata record or the DOI syntax or both.
This document does not specify particular technologies to implement the syntax, description and
resolution functional components of the digital object identifier system.
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.
UNICODE CONSORTIUM The Unicode® Standard. Mountain View, California: Unicode Consortium.
Latest edition available at: https:// www .unicode .org/ versions/ latest/
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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 https:// www .electropedia .org/
3.1
DOI system
social and technical infrastructure for the assignment and administration of DOI names (3.2)
as identifiers in computer-readable form through assignment, resolution, referent description,
administration, etc.
3.2
DOI name
string that specifies a unique object (3.3) within the DOI system (3.1)
Note 1 to entry: Names consist of characters in a sequence specified by the DOI syntax (3.4).
1
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ISO 26324:2022(E)
Note 2 to entry: The terms “identifier” and “number” are sometimes but not always used in the same sense and
are to be avoided where ambiguity can arise. The unqualified use of “DOI” alone can also be ambiguous. Therefore
“DOI” is always used in conjunction with a specific noun such as DOI name (3.2) or DOI system (3.1) unless the
meaning is sufficiently clear from an earlier mention or the specific context.
3.3
object
entity within the scope of the DOI system (3.1) that can be digital, physical or abstract
Note 1 to entry: Digital, physical or abstract forms of an entity can be of relevance in information and
documentation (e.g. resources, people or agreements).
Note 2 to entry: A particular object identified by a specific DOI name (3.2) is the referent (3.16) of that DOI name.
3.4
DOI syntax
rules for the form and sequence of characters comprising any DOI name (3.2), specifically the form and
character of a prefix element, separator and suffix element
3.5
directory indicator
unique string allocated to a registrant for the purpose of assignment of DOI names, forming part of the
prefix element of the DOI syntax (3.4) but having no other implied meaning
3.6
registrant code
unique string assigned to a registrant, forming part of the prefix element of the DOI syntax (3.4) but
having no other implied meaning
3.7
DOI metadata
specific data associated with a referent within the DOI system (3.1), based on a structured data model
that enables the referent of the DOI name (3.2) to be associated with data of any desired degree of
precision and granularity to support identification, description and services
Note 1 to entry: DOI metadata is specified in Annex B.
3.8
DOI kernel metadata
subset of DOI metadata (3.7) that is common to all DOI name assignments
Note 1 to entry: DOI kernel metadata is specified in Annex B.
3.9
application profile
set of DOI names (3.2) that share some common characteristics
Note 1 to entry: A DOI application profile is a grouping mechanism for DOI names (3.2); the functional
specification of the application profile includes a set of DOI metadata, comprising the DOI kernel metadata and
additional information applicable to that particular genre of object and functional requirements. Each DOI name
is associated with one or more application profiles.
3.10
data dictionary
repository for all data elements and allowed values (3.11) of those elements used in DOI metadata
specifications
3.11
allowed value
item which may be used as a value of an element
2
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ISO 26324:2022(E)
3.12
opaque string
syntax string that has no meaning discernible by simple inspection
Note 1 to entry: To discover meaning, there is a need to refer to metadata.
3.13
registrant
person or organization that has requested and received the registration of a particular DOI name (3.2)
3.14
interoperability
ability of independent systems to exchange meaningful information and initiate actions from each
other, in order to operate together to mutual benefit
Note 1 to entry: In particular, interoperability constitutes the ability for loosely-coupled independent systems to
be able to collaborate and communicate. See Reference [14] for further information about interoperability.
3.15
resolution
process of submitting a DOI name (3.2) to a network service and receiving in return one or more pieces
of current information related to the identified object such as metadata or a location of the object or of
metadata
Note 1 to entry: This can involve one or more intermediate mapping operations. The resolution might or might
not return an instance of the object. Multiple resolution is the simultaneous return as output of several pieces of
current information related to the object, in defined data structures.
3.16
referent
particular object (3.3) identified by a DOI name (3.2)
3.17
unique identification
specification by a DOI name (3.2) of one and only one referent (3.16)
3.18
persistent
existence, and ability to be used in services outside the direct control of the issuing assigner, without a
stated time limit
3.19
first class
having an identity of itself, not as some attribute of an object
Note 1 to entry: An address is an attribute of something, whereas the thing that has this attribute is a first class
object. A DOI name references an entity as a first-class object, not simply the place where the object is located. It
may then resolve to a location.
4 DOI name
4.1 Syntax
4.1.1 General characteristics
The DOI syntax shall be made up of a DOI prefix and a DOI suffix separated by a forward slash.
There is no defined limit on the length of the DOI name, or of the DOI prefix or DOI suffix.
3
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ISO 26324:2022(E)
The DOI name shall be case-insensitive and shall contain only printable characters from the legal
graphic characters specified by the Unicode Standard. Further constraints on character use (e.g. use
of language-specific alphanumeric characters) can be defined for an application by the ISO 26324
Registration Authority.
The combination of a unique DOI prefix (assigned to a particular DOI registrant) and a unique DOI
suffix (provided by that registrant for a specific object) shall be unique. This allows the de-centralized
allocation of DOI names. The registration of the combination of the prefix and suffix in the DOI system
also serves to validate the DOI syntax for a given DOI name.
The DOI name shall be regarded as an opaque string by users of the DOI system. No definitive information
shall be inferred from the specific character string of a DOI name. In particular, the inclusion in a DOI
name of any DOI prefix allocated to a specific registrant does not provide evidence of the ownership
of rights or current management responsibility of any intellectual property in the referent. The mere
assignment of a DOI name to a referent shall not imply endorsement of the referent by any party. Such
information may be asserted in the associated DOI metadata.
4.1.2 DOI prefix
4.1.2.1 Elements
4.1.2.1.1 General
The DOI prefix shall be composed of a directory indicator optionally followed by a registrant code.
Where a registrant code is present, the two components shall be separated by a full stop (period).
The DOI prefix is a unique string allocated to a registrant.
4.1.2.1.2 Directory indicator
The directory indicator shall be allocated, optionally with a registrant code, to a registrant by the
ISO 26324 Registration Authority for the purpose of the assignment of DOI names.
Where a registrant code was allocated to a registrant under a previous edition of this document, the
assignment of “10” as the directory indicator shall be assumed.
Information on the implications of allocating a directory indicator other than “10” is contained in
Annex D.
A user of the DOI system can determine whether a directory indicator is valid for use in DOI names
by consulting the register managed by the ISO 26324 Registration Authority in accordance with the
requirement in C.2.
4.1.2.1.3 Registrant code
Where present, the second element of the DOI prefix shall be the registrant code allocated by the
ISO 26324 Registration Authority. A registrant code shall always be used with the directory indicator
with which it is allocated.
EXAMPLE 1
10.1000 DOI prefix comprising a directory indicator “10” followed by registrant code “1000”.
The registrant code may be further divided into sub-elements for administrative convenience if
desired. Each sub-element of the registrant code shall be preceded by a full stop. Such subdivision
implies no hierarchical relationship; each registrant code, whether subdivided or not, has equal status
in the DOI system. However, a subdivided registrant code can have technical resolution implications. It
4
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ISO 26324:2022(E)
is recommended that registrants consult the ISO 26324 Registration Authority for further information
about assignment of registrant codes.
EXAMPLE 2
10.1000.11 DOI prefix in which the registrant code (“1000.11”) has a subdivision “11”.
The registrant code shall be omitted where a directory indicator has been assigned without one.
EXAMPLE 3
15434 DOI prefix consisting of only a directory indicator where no registrant code has been
assigned.
4.1.2.2 Changes
Once a DOI name has been assigned, it shall not be changed regardless of any changes in the ownership
or management of the referent.
NOTE The original registrant might no longer have any role in maintaining a DOI name and its associated
records even though its registrant code remains a permanent element of that DOI name.
4.1.3 DOI suffix
The DOI suffix shall consist of a character string of any length chosen by the registrant. Each suffix
shall be unique to the prefix element that precedes it. The unique suffix can be a sequential number, or
it might incorporate an identifier generated from or based on another system used by the registrant,
[5][6] [3] [2] [10]
such as ISAN , ISRC , ISSN , ISNI ; in such cases, a preferred construction for such a suffix may
be specified by the ISO 26324 Registration Authority as in Example 2. When constructing DOI names
from other identifier systems, including schemes where the DOI prefix is affected, the procedures in
Annex A shall be followed.
EXAMPLE 1
10.1000/123456 DOI name with the DOI prefix “10.1000” and the DOI suffix “123456”.
EXAMPLE 2
10.1038/issn.1476-4687 DOI suffix using an ISSN. According to the construction used here, a DOI suffix
is assembled using an ISSN by preceding the ISSN (including the hyphen) with
the lowercase letters “issn” and a period. This hypothetical example is a DOI
for the electronic version of Nature.
4.2 Visual presentation and other representation of DOI names
4.2.1 Screen and print presentation
When displayed on screen or in print, a DOI name shall be preceded by a lowercase “doi:” unless the
context clearly indicates that a DOI name is implied. The "doi:” label is not part of the DOI name value.
EXAMPLE
The DOI name “10.1006/jmbi.1998.2354” is displayed and printed as "doi: 10 .1006/ jmbi .1998 .2354".
4.2.2 URI presentation
[13]
The use of the lowercase string “doi” complies with the syntax of IETF specification, RFC 3986, for
representation as a URI (uniform resource identifier), such as “ftp:” and “http:”.
5
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ISO 26324:2022(E)
When displayed in web browsers, the DOI name can be attached to the address for an appropriate
proxy server, to enable resolution of the DOI name via a standard web hyperlink. To resolve a DOI via
a standard web hyperlink, the DOI name itself should be appended to the address for the proxy server.
EXAMPLE
The DOI name “10.1006/jmbi.1998.2354” would be made an actionable link as “https:// doi .org/ 10 .1006/
jmbi .1998 .2354”.
DOI names so represented in a URL and transported by the HTTP protocol are constrained to follow
standard IETF guidelines for URI representations. The syntax for URIs is more restrictive than the
syntax for DOIs; some characters are reserved and will need percent-encoding.
NOTE Certain client or server software might be able to process DOIs using native resolution technology
(i.e. doi: 10 .1006/ jmbi .1998 .2354 would be interpreted by the browser and automatically resolved without the
addition of the proxy server address).
4.2.3 Other representations
DOI names can be represented in other forms in certain contexts.
Characters which cannot be handled directly in a specific network or reference context, or where
ambiguity can arise (e.g. minus sign, the hyphen, and the en-dash all look similar on the screen but
carry different character values) should be avoided or encoded in an appropriate way (e.g. for URLs
convert to UTF-8 and then percent-encode).
5 Assignment of DOI name
5.1 Principles of assignment
[5][6] [1]
A DOI name shall not be used as a replacement for other ISO identifier schemes such as ISAN, ISBN,
[3] [2] [10]
ISRC, ISSN, ISNI and other commonly recognized identifiers. When constructing DOI names from
other identifier systems, including schemes where the DOI prefix is affected, the procedures in Annex A
shall be followed. It also contains requirements for an alternative approach where the identifier from
another system is indicated in DOI metadata.
A DOI name may be assigned to any object whenever there is a functional need to distinguish it from
other objects.
“DOI” shall be construed as “digital identifier of an object” (not “identifier of a digital object”).
Rules for assignment of DOI names can include a functional definition of scope based on appropriate
DOI metadata through a DOI application profile.
5.2 Granularity
A DOI name may be assigned to any object, regardless of the extent to which that object might be a
component part of some larger entity. DOI names may be assigned at any desired degree of precision
and granularity that a registrant deems to be appropriate.
EXAMPLE For granularity in textual materials, separate DOI names can be assigned to:
— a novel as an abstract work,
— a specific edition of that novel,
— a specific chapter within that edi
...

SLOVENSKI STANDARD
oSIST ISO/DIS 26324:2022
01-februar-2022
Informatika in dokumentacija - Sistem identifikatorjev digitalnega objekta
Information and documentation -- Digital object identifier system
Information et documentation -- Système d'identifiant numérique d'objet
Ta slovenski standard je istoveten z: ISO/DIS 26324
ICS:
01.140.20 Informacijske vede Information sciences
oSIST ISO/DIS 26324:2022 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST ISO/DIS 26324:2022

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oSIST ISO/DIS 26324:2022
DRAFT INTERNATIONAL STANDARD
ISO/DIS 26324
ISO/TC 46/SC 9 Secretariat: ANSI
Voting begins on: Voting terminates on:
2021-10-07 2021-12-30
Information and documentation — Digital object identifier
system
Information et documentation — Système d'identifiant numérique d'objet
ICS: 01.140.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 26324:2021(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2021

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oSIST ISO/DIS 26324:2022
ISO/DIS 26324:2021(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

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oSIST ISO/DIS 26324:2022
ISO/DIS 26324:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 DOI name . 3
4.1 Syntax . 3
4.1.1 General characteristics . 3
4.1.2 DOI prefix . 4
4.1.3 DOI suffix . 5
4.2 Visual presentation and other representation of DOI names . 5
4.2.1 Screen and print presentation . 5
4.2.2 URI presentation . 5
4.2.3 Other representations . 5
5 Assignment of DOI name . 6
5.1 Principles of assignment . 6
5.2 Granularity . 6
5.3 Description . 6
5.4 Uniqueness . 6
5.5 Persistence. 6
6 Resolution of DOI name . 7
6.1 General . 7
6.2 Functionality . 7
7 DOI metadata . 8
7.1 General . 8
7.2 Functionality . 8
7.3 Registration of DOI metadata . 9
8 Administration of the DOI system . 9
Annex A (normative) Relationship between the DOI system and other identifier schemes .10
Annex B (normative) DOI metadata specification .12
Annex C (normative) Administration of the DOI system .14
Annex D (informative) Transition from ISO 26324:2012 to ISO 26324:20xx .16
Bibliography .18
© ISO 2021 – All rights reserved iii

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oSIST ISO/DIS 26324:2022
ISO/DIS 26324:2021(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
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.
ISO 26324 was prepared by Technical Committee ISO/TC 46, Information and documentation,
Subcommittee SC 9, Identification and description.
This second edition cancels and replaces the first edition (ISO 26324:2012), which has been technically
revised. The substantive change affecting users is the removal of the requirement that the directory
indicator be “10”. The registration authority now has the ability to assign DOI prefixes with a directory
indicator other than “10”, allowing certain existing identification schemes to become part of the DOI
system.
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 © ISO 2021 – All rights reserved

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oSIST ISO/DIS 26324:2022
ISO/DIS 26324:2021(E)

Introduction
1)
The digital object identifier [DOI® ] system provides an infrastructure for persistent unique
identification of objects of any type.
DOI is an acronym for “digital object identifier”, meaning a “digital identifier of an object” rather than an
“identifier of a digital object”. In this International Standard, the term “digital object identifier” refers to
the system defined in this International Standard unless otherwise stated. The DOI system was initiated
by the International DOI Foundation in 1998, and initially developed with the collaboration of some
participants in ISO/TC 46/SC 9. Due to its application in the fields of information and documentation
and previous collaboration with some ISO/TC 46/SC 9 participants, it was introduced as a possible
work item in 2004 and further developed from 2006 to 2010.
The DOI system is designed to work over the Internet. A DOI name is permanently assigned to an object
to provide a resolvable persistent network link to current information about that object, including
where the object, or information about it, can be found on the Internet. While information about an
object can change over time, its DOI name will not change. A DOI name can be resolved within the DOI
system to values of one or more types of data relating to the object identified by that DOI name, such as
a URL, an e-mail address, other identifiers and descriptive metadata.
The DOI system enables the construction of automated services and transactions. Applications of
the DOI system include but are not limited to managing information and documentation location and
access; managing metadata; facilitating electronic transactions; persistent unique identification of any
form of any data; and commercial and non-commercial transactions.
The content of an object associated with a DOI name is described unambiguously by DOI metadata,
based on a structured extensible data model that enables the object to be associated with metadata of
any desired degree of precision and granularity to support description and services. The data model
supports interoperability between DOI applications.
The scope of the DOI system is not defined by reference to the type of content (format, etc.) of the
referent, but by reference to the functionalities it provides and the context of use. The DOI system
provides, within networks of DOI applications, for unique identification, persistence, resolution,
metadata and semantic interoperability.
1) DOI® is a registered trademark. Information concerning trademark issues can be found on ISO online webpage
for the ISO 26324 Registration authority at http:// www .iso.or g/ iso/ maintenance _agencies.html. EDITOR’S NOTE:
This address is incorrect and the correct address (https:// www .iso.or g/ maintenance _agencies.html) does not
contain this information.
© ISO 2021 – All rights reserved v

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oSIST ISO/DIS 26324:2022

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oSIST ISO/DIS 26324:2022
DRAFT INTERNATIONAL STANDARD ISO/DIS 26324:2021(E)
Information and documentation — Digital object identifier
system
1 Scope
This International Standard specifies the syntax, description and resolution functional components
of the digital object identifier system, and the general principles for the creation, registration and
administration of DOI names (where DOI is an acronym for “digital object identifier”).
This International Standard defines the syntax for a DOI name, which is used for the identification of an
object of any material form (digital or physical) or an abstraction (such as a textual work) where there
is a functional need to distinguish it from other objects.
The DOI name does not replace, nor is it an alternative for, an identifier used in another scheme, such as
the schemes defined by ISO/TC 46/SC 9. This International Standard describes how the DOI system can
be used in conjunction with another identifier scheme (for example, to provide additional functionality,
such as resolution, where this is not already available), and how the character string of that other
scheme can be integrated into the DOI system through the DOI metadata record and/or the DOI syntax.
This International Standard does not specify specific technologies to implement the syntax, description
and resolution functional components of the digital object identifier system.
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.
TM 2)
Unicode Consortium The Unicode Standard
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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 https:// www .electropedia .org/
3.1
allowed value
item which may be used as a value of an element
3.2
application profile
set of DOI names that share some common characteristics
Note 1 to entry: A DOI application profile is a grouping mechanism for DOI names; the functional specification
of the application profile includes a set of metadata, comprising the kernel metadata and additional information
applicable to that particular genre of object and functional requirements. Each DOI name is associated with one
or more application profiles.
2) Available at: http:// www .unicode.or g. Unicode is a trademark of Unicode, Inc. The Unicode Standard imposes
additional constraints on implementations of ISO/IEC 10646:2011.
© ISO 2021 – All rights reserved 1

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3.3
data dictionary
repository for all data elements and allowed values of those elements used in DOI metadata
specifications
3.4
directory indicator
unique string assigned to a registrant, forming part of the prefix element of the DOI syntax (3.6) but
having no other implied meaning
3.5
DOI name
string that specifies a unique object (3.10) within the DOI system (3.7)
Note 1 to entry: Names consist of characters in a sequence specified by the DOI syntax (3.6).
Note 2 to entry: The terms “identifier” and “number” are sometimes but not always used in the same sense
and are to be avoided where ambiguity can arise. The unqualified use of “DOI” alone can also be ambiguous.
Therefore “DOI” is always used in conjunction with a specific noun [e.g. DOI name (3.5), DOI system (3.7)] unless
the meaning is sufficiently clear from an earlier mention or the specific context.
3.6
DOI syntax
rules for the form and sequence of characters comprising any DOI name (3.5), specifically the form and
character of a prefix element, separator and suffix element
3.7
DOI system
social and technical infrastructure for the assignment and administration of DOI names (3.5)
as identifiers in computer-readable form through assignment, resolution, referent description,
administration, etc.
3.8
interoperability
ability of independent systems to exchange meaningful information and initiate actions from each
other, in order to operate together to mutual benefit
Note 1 to entry: In particular, interoperability constitutes the ability for loosely-coupled independent systems to
be able to collaborate and communicate. See Reference [17] for further information about interoperability.
3.9
metadata
specific data associated with a referent within the DOI system (3.7), based on a structured data model
that enables the referent of the DOI name (3.5) to be associated with data of any desired degree of
precision and granularity to support identification, description and services
Note 1 to entry: This can involve one or more intermediate mapping operations. The resolution might or might
not return an instance of the object. Multiple resolution is the simultaneous return as output of several pieces of
current information related to the object, in defined data structures.
3.10
object
entity within the scope of the DOI system (3.7) that can be digital, physical or abstract
Note 1 to entry: Digital, physical or abstract forms of an entity can be of relevance in information and
documentation (e.g. resources, people or agreements).
Note 2 to entry: A particular object identified by a specific DOI name (3.5) is the referent (3.13) of that DOI name.
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3.11
opaque string
syntax string that has no meaning discernible by simple inspection
Note 1 to entry: To discover meaning, metadata are required.
3.12
persistent
existence, and ability to be used in services outside the direct control of the issuing assigner, without a
stated time limit
3.13
referent
particular object (3.10) identified by a DOI name (3.5)
3.14
registrant
person or organization that has requested and received the registration of a particular DOI name (3.5)
3.15
registrant code
unique string assigned to a registrant, forming part of the prefix element of the DOI syntax (3.6) but
having no other implied meaning
3.16
resolution
process of submitting a DOI name (3.5) to a network service and receiving in return one or more pieces
of current information related to the identified object such as metadata or a location (URL) of the object
or of metadata
3.17
unique identification
specification by a DOI name (3.5) of one and only one referent (3.13)
4 DOI name
4.1 Syntax
4.1.1 General characteristics
The DOI syntax shall be made up of a DOI prefix and a DOI suffix separated by a forward slash.
There is no defined limit on the length of the DOI name, or of the DOI prefix or DOI suffix.
The DOI name is case-insensitive and can incorporate any printable characters from the legal graphic
characters of Unicode. Further constraints on character use (e.g. use of language-specific alphanumeric
characters) can be defined for an application by the ISO 26324 Registration authority.
The combination of a unique DOI prefix (assigned to a particular DOI registrant) and a unique DOI suffix
(provided by that registrant for a specific object) is unique, and so allows the de-centralized allocation
of DOI names.
The DOI name is an opaque string for the purposes of the DOI system. No definitive information may be
inferred from the specific character string of a DOI name. In particular, the inclusion in a DOI name of
any DOI prefix allocated to a specific registrant does not provide evidence of the ownership of rights or
current management responsibility of any intellectual property in the referent. The mere assignment
of a DOI name to a referent does not imply endorsement of the referent by any party. Such information
may be asserted in the associated metadata.
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4.1.2 DOI prefix
4.1.2.1 Elements
4.1.2.1.1 General
The DOI prefix shall be composed of a directory indicator optionally followed by a registrant code.
Where a registrant code is present, the two components shall be separated by a full stop (period).
The DOI prefix is a unique string assigned to a registrant.
4.1.2.1.2 Directory indicator
The directory indicator shall be assigned, optionally with a registrant code, to a registrant by the
ISO 26324 Registration authority.
Where a registrant code was assigned to a registrant under a previous edition of this document, the
assignment of “10” as the directory indicator shall be assumed.
4.1.2.1.3 Registrant code
Where present, the second element of the DOI prefix shall be the registrant code.
EXAMPLE 1
10.1000 DOI prefix comprising a directory indicator “10” followed by registrant code “1000”.
The registrant code may be further divided into sub-elements for administrative convenience if
desired. Each sub-element of the registrant code shall be preceded by a full stop. Such subdivision
implies no hierarchical relationship; each registrant code, whether subdivided or not, has equal status
in the DOI system. However a subdivided registrant code can have technical resolution implications. It
is recommended that registrants consult the ISO 26324 Registration authority for further information
about assignment of registrant codes.
EXAMPLE 2
10.1000.11 DOI prefix in which the registrant code has a subdivision “11”.
The registrant code may be omitted where a directory indicator has been assigned without one.
EXAMPLE 3
15434 DOI prefix consisting of only a directory indicator where no registrant code has been
assigned.
EDITOR’S NOTE: make sure this prefix (15434) is unused in the Handle system to avoid implications
that a particular Handle application has joined the DOI system.
4.1.2.2 Changes
Once a DOI name has been assigned it shall not be changed, regardless of any changes in the ownership
or management of the referent.
NOTE The original registrant might no longer have any role in maintaining a DOI name and its associated
records even though its registrant code remains a permanent element of that DOI name.
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4.1.3 DOI suffix
The DOI suffix shall consist of a character string of any length chosen by the registrant. Each suffix
shall be unique to the prefix element that precedes it. The unique suffix can be a sequential number, or
it might incorporate an identifier generated from or based on another system used by the registrant,
[5][6] [1] [3] [2] [10] [11]
e.g. ISAN , ISBN , ISRC , ISSN , ISTC , ISNI ; in such cases, a preferred construction for such
a suffix can be specified, as in Example 2. See Annex A for further details.
EXAMPLE 1
10.1000/123456 DOI name with the DOI prefix “10.1000” and the DOI suffix “123456”.
EXAMPLE 2
10.1038/issn.1476-4687 DOI suffix using an ISSN. To construct a DOI suffix using an ISSN, precede the
ISSN (including the hyphen) with the lowercase letters “issn” and a period,
as in this hypothetical example of a DOI for the electronic version of Nature.
4.2 Visual presentation and other representation of DOI names
4.2.1 Screen and print presentation
When displayed on screen or in print, a DOI name shall be preceded by a lowercase “doi:” unless the
context clearly indicates that a DOI name is implied. The "doi:” label is not part of the DOI name value.
EXAMPLE
The DOI name “10.1006/jmbi.1998.2354” is displayed and printed as "doi: 10.1006/jmbi.1998.2354".
4.2.2 URI presentation
[14]
The use of the lowercase string “doi” complies with the IETF specification, RFC 3986 , for
representation as a URI (uniform resource identifier), such as “ftp:” and “http:”.
When displayed in web browsers, the DOI name can be attached to the address for an appropriate
proxy server, to enable resolution of the DOI name via a standard web hyperlink. To resolve a DOI via
a standard web hyperlink, the DOI name itself should be appended to the address for the proxy server.
EXAMPLE
The DOI name “10.1006/jmbi.1998.2354” would be made an actionable link as “https:// doi .org/ 10 .1006/
jmbi .1998 .2354”.
DOI names so represented in a URL and transported by the HTTP protocol are constrained to follow
standard IETF guidelines for URI representations. The syntax for URIs is more restrictive than the
syntax for DOIs; some characters are reserved and will need percent-encoding.
NOTE Certain client or server software might be able to process DOIs using native resolution technology
(i.e. doi: 10.1006/jmbi.1998.2354 would be interpreted by the browser and automatically resolved without the
addition of the proxy server address).
4.2.3 Other representations
DOI names can be represented in other forms in certain contexts (e.g. in the info URI scheme RFC 4452
[15]
).
NOTE The registration of the DOI system within the info URI scheme remains valid but the new registrations
are not being accepted and users are being advised to migrate their applications to “mainstream Web practices”.
[18]
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Characters which cannot be handled directly in a specific network or reference context, or where
ambiguity can arise (e.g. minus sign, the hyphen, and the en-dash all look similar on the screen but
carry different character values) should be avoided or encoded in an appropriate way (e.g. for URLs
convert to UTF-8 and then percent-encode).
5 Assignment of DOI name
5.1 Principles of assignment
[5][6]
A DOI name shall not be used as a replacement for other ISO identifier schemes such as ISAN ,
[1] [3] [2] [10] [11]
ISBN , ISRC , ISSN , ISTC , ISNI and other commonly recognized identifiers. See Annex A for
further details.
A DOI name can be assigned to any object whenever there is a functional need to distinguish it from
other objects.
“DOI” is construed as “digital identifier of an object” (not “identifier of a digital object”).
Rules for assignment of DOI names can include a functional definition of scope based on appropriate
metadata through a DOI application profile.
5.2 Granularity
A DOI name can be assigned to any object, regardless of the extent to which that object might be a
component part of some larger entity. DOI names can be assigned at any desired degree of precision
and granularity that a registrant deems to be appropriate.
EXAMPLE For granularity in textual materials, separate DOI names can be assigned to:
— a novel as an abstract work,
— a specific edition of that novel,
— a specific chapter within that edition of the novel,
— a single paragraph,
— a specific image, or
— a quotation,
as well as to each specific manifestation in which any of those entities are published or otherwise made available.
5.3 Description
The assignment of a DOI name requires that the registrant provide metadata describing the object to
which the DOI name is being assigned. The metadata shall describe the object to the degree that is
necessary to distinguish it as a separate entity within the DOI
...