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1. Digital object identifier
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For the use of digital object identifiers on Wikipedia, see Wikipedia:Digital Object
Identifier.
Digital object identifier
Acronym DOI
Organisation International DOI Foundation
Introduced 2000; 22 years ago
Example 10.1000/182
Website www.doi.org
A digital object identifier (DOI) is a persistent identifier or handle used to uniquely
identify various objects, standardized by the International Organization for
Standardization (ISO).[1]
DOIs are an implementation of the Handle System;[2][3]
they
also fit within the URI system (Uniform Resource Identifier). They are widely used to
identify academic, professional, and government information, such
as journal articles, research reports, data sets, and official publications. DOIs have
also been used to identify other types of information resources, such as commercial
videos.
A DOI aims to resolve to its target, the information object to which the DOI refers.
This is achieved by binding the DOI to metadata about the object, such as
a URL where the object is located. Thus, by being actionable and interoperable, a
DOI differs from ISBNs or ISRCs which are identifiers only. The DOI system uses
the indecs Content Model for representing metadata.
The DOI for a document remains fixed over the lifetime of the document, whereas its
location and other metadata may change. Referring to an online document by its DOI
should provide a more stable link than directly using its URL. But if its URL changes,
the publisher must update the metadata for the DOI to maintain the link to the

2. URL.[4][5][6]
It is the publisher's responsibility to update the DOI database. If they fail to
do so, the DOI resolves to a dead link leaving the DOI useless.[7]
The developer and administrator of the DOI system is the International DOI
Foundation (IDF), which introduced it in 2000.[8]
Organizations that meet the
contractual obligations of the DOI system and are willing to pay to become a
member of the system can assign DOIs.[9]
The DOI system is implemented through a
federation of registration agencies coordinated by the IDF.[10]
By late April 2011 more
than 50 million DOI names had been assigned by some 4,000 organizations,[11]
and
by April 2013 this number had grown to 85 million DOI names assigned through
9,500 organizations.
Contents
 1Nomenclature and syntax
o 1.1Display
 2Content
 3Features and benefits
 4Comparison with other identifier schemes
 5Resolution
 6IDF organizational structure
 7Standardization
 8See also
 9Notes
 10References
 11External links
Nomenclature and syntax[edit]
A DOI is a type of Handle System handle, which takes the form of a character
string divided into two parts, a prefix and a suffix, separated by a slash.
prefix/suffix
The prefix identifies the registrant of the identifier and
the suffix is chosen by the registrant and identifies the
specific object associated with that DOI. Most
legal Unicode characters are allowed in these strings,
which are interpreted in a case-insensitive manner. The
prefix usually takes the form 10.NNNN , where NNNN is at
least a four digit number greater than or equal to 1000 ,
whose limit depends only on the total number of
registrants.[12][13]
The prefix may be further subdivided
with periods, like 10.NNNN.N .[14]
For example, in the DOI name 10.1000/182 , the prefix
is 10.1000 and the suffix is 182 . The "10" part of the
prefix distinguishes the handle as part of the DOI
namespace, as opposed to some other Handle System
namespace,[A]
and the characters 1000 in the prefix
identify the registrant; in this case the registrant is the

3. International DOI Foundation itself. 182 is the suffix, or
item ID, identifying a single object (in this case, the
latest version of the DOI Handbook).
DOI names can identify creative works (such as texts,
images, audio or video items, and software) in both
electronic and physical forms, performances, and
abstract works[15]
such as licenses, parties to a
transaction, etc.
The names can refer to objects at varying levels of
detail: thus DOI names can identify a journal, an
individual issue of a journal, an individual article in the
journal, or a single table in that article. The choice of
level of detail is left to the assigner, but in the DOI
system it must be declared as part of the metadata that
is associated with a DOI name, using a data
dictionary based on the indecs Content Model.
Display[edit]
The official DOI Handbook explicitly states that DOIs
should display on screens and in print in the
format doi:10.1000/182 .[16]
Contrary to the DOI Handbook, CrossRef, a major DOI
registration agency, recommends displaying a URL (for
example, https://doi.org/10.1000/182 ) instead of the
officially specified format (for
example, doi:10.1000/182 )[17][18]
This URL is persistent
(there is a contract that ensures persistence in the
DOI.ORG domain), so it is a PURL – providing the
location of an HTTP proxy server which will redirect web
accesses to the correct online location of the linked
item.[9][19]
The CrossRef recommendation is primarily based on
the assumption that the DOI is being displayed without
being hyperlinked to its appropriate URL – the argument
being that without the hyperlink it is not as easy to copy-
and-paste the full URL to actually bring up the page for
the DOI, thus the entire URL should be displayed,
allowing people viewing the page containing the DOI to
copy-and-paste the URL, by hand, into a new
window/tab in their browser in order to go to the
appropriate page for the document the DOI
represents.[20]
Since DOI is a namespace within the Handle system, it
is semantically correct to represent it as the
URI info:doi/10.1000/182 .
Content[edit]

4. Major content of the DOI system currently includes:
 Scholarly materials (journal articles, books, ebooks,
etc.) through Crossref, a consortium of around 3,000
publishers; Airiti, a leading provider of Chinese and
Taiwanese electronic academic journals; and the
Japan Link Center (JaLC) [21]
an organization
providing link management and DOI assignment for
electronic academic journals in Japanese.
 Research datasets through Datacite, a consortium of
leading research libraries, technical information
providers, and scientific data centers;
 European Union official publications through the EU
publications office;
 The Chinese National Knowledge
Infrastructure project at Tsinghua University and
the Institute of Scientific and Technical Information
of China (ISTIC), two initiatives sponsored by the
Chinese government.
 Permanent global identifiers for both commercial and
non-commercial audio/visual content titles, edits,
and manifestations through the Entertainment ID
Registry, commonly known as EIDR.
In the Organisation for Economic Co-operation and
Development's publication service OECD iLibrary, each
table or graph in an OECD publication is shown with a
DOI name that leads to an Excel file of data underlying
the tables and graphs. Further development of such
services is planned.[22]
Other registries include Crossref and the multilingual
European DOI Registration Agency (mEDRA).[23]
Since
2015, RFCs can be referenced
as doi:10.17487/rfc... .[24]
Features and benefits[edit]
The IDF designed the DOI system to provide a form
of persistent identification, in which each DOI name
permanently and unambiguously identifies the object to
which it is associated (although when the publisher of a
journal changes, sometimes all the DOIs will be
changed, with the old DOIs no longer working). It also
associates metadata with objects, allowing it to provide
users with relevant pieces of information about the
objects and their relationships. Included as part of this
metadata are network actions that allow DOI names to
be resolved to web locations where the objects they
describe can be found. To achieve its goals, the DOI

5. system combines the Handle System and the indecs
Content Model with a social infrastructure.
The Handle System ensures that the DOI name for an
object is not based on any changeable attributes of the
object such as its physical location or ownership, that
the attributes of the object are encoded in its metadata
rather than in its DOI name, and that no two objects are
assigned the same DOI name. Because DOI names are
short character strings, they are human-readable, may
be copied and pasted as text, and fit into
the URI specification. The DOI name-resolution
mechanism acts behind the scenes, so that users
communicate with it in the same way as with any other
web service; it is built on open architectures,
incorporates trust mechanisms, and is engineered to
operate reliably and flexibly so that it can be adapted to
changing demands and new applications of the DOI
system.[25]
DOI name-resolution may be used
with OpenURL to select the most appropriate among
multiple locations for a given object, according to the
location of the user making the request.[26]
However,
despite this ability, the DOI system has drawn criticism
from librarians for directing users to non-free copies of
documents, that would have been available for no
additional fee from alternative locations.[27]
The indecs Content Model as used within the DOI
system associates metadata with objects. A small kernel
of common metadata is shared by all DOI names and
can be optionally extended with other relevant data,
which may be public or restricted. Registrants may
update the metadata for their DOI names at any time,
such as when publication information changes or when
an object moves to a different URL.
The International DOI Foundation (IDF) oversees the
integration of these technologies and operation of the
system through a technical and social infrastructure.
The social infrastructure of a federation of independent
registration agencies offering DOI services was
modelled on existing successful federated deployments
of identifiers such as GS1 and ISBN.
Comparison with other identifier
schemes[edit]
A DOI name differs from commonly used Internet
pointers to material, such as the Uniform Resource
Locator (URL), in that it identifies an object itself as
a first-class entity, rather than the specific place where

6. the object is located at a certain time. It implements
the Uniform Resource Identifier (Uniform Resource
Name) concept and adds to it a data model and social
infrastructure.[28]
A DOI name also differs from standard identifier
registries such as the ISBN, ISRC, etc. The purpose of
an identifier registry is to manage a given collection of
identifiers, whereas the primary purpose of the DOI
system is to make a collection of identifiers actionable
and interoperable, where that collection can include
identifiers from many other controlled collections.[29]
The DOI system offers persistent, semantically
interoperable resolution to related current data and is
best suited to material that will be used in services
outside the direct control of the issuing assigner (e.g.,
public citation or managing content of value). It uses a
managed registry (providing social and technical
infrastructure). It does not assume any specific business
model for the provision of identifiers or services and
enables other existing services to link to it in defined
ways. Several approaches for making identifiers
persistent have been proposed. The comparison of
persistent identifier approaches is difficult because they
are not all doing the same thing. Imprecisely referring to
a set of schemes as "identifiers" doesn't mean that they
can be compared easily. Other "identifier systems" may
be enabling technologies with low barriers to entry,
providing an easy to use labeling mechanism that allows
anyone to set up a new instance (examples
include Persistent Uniform Resource Locator (PURL),
URLs, Globally Unique Identifiers (GUIDs), etc.), but
may lack some of the functionality of a registry-
controlled scheme and will usually lack accompanying
metadata in a controlled scheme. The DOI system does
not have this approach and should not be compared
directly to such identifier schemes. Various applications
using such enabling technologies with added features
have been devised that meet some of the features
offered by the DOI system for specific sectors
(e.g., ARK).
A DOI name does not depend on the object's location
and, in this way, is similar to a Uniform Resource
Name (URN) or PURL but differs from an ordinary URL.
URLs are often used as substitute identifiers for
documents on the Internet although the same document
at two different locations has two URLs. By contrast,
persistent identifiers such as DOI names identify objects
as first class entities: two instances of the same object
would have the same DOI name.

7. Resolution[edit]
DOI name resolution is provided through the Handle
System, developed by Corporation for National
Research Initiatives, and is freely available to any user
encountering a DOI name. Resolution redirects the user
from a DOI name to one or more pieces of typed data:
URLs representing instances of the object, services
such as e-mail, or one or more items of metadata. To
the Handle System, a DOI name is a handle, and so has
a set of values assigned to it and may be thought of as
a record that consists of a group of fields. Each handle
value must have a data type specified in
its <type> field, which defines the syntax and semantics
of its data. While a DOI persistently and uniquely
identifies the object to which it is assigned, DOI
resolution may not be persistent, due to technical and
administrative issues.
To resolve a DOI name, it may be input to a DOI
resolver, such as doi.org.
Another approach, which avoids typing or cutting-and-
pasting into a resolver is to include the DOI in a
document as a URL which uses the resolver as an
HTTP proxy, such
as https://doi.org/ (preferred)[30]
or http://dx.doi.o
rg/ , both of which support HTTPS. For example, the
DOI 10.1000/182 can be included in a reference
or hyperlink as https://doi.org/10.1000/182 . This
approach allows users to click on the DOI as a
normal hyperlink. Indeed, as previously mentioned, this
is how CrossRef recommends that DOIs always be
represented (preferring HTTPS over HTTP), so that if
they are cut-and-pasted into other documents, emails,
etc., they will be actionable.
Other DOI resolvers and HTTP Proxies include
the Handle System and PANGAEA. At the beginning of
the year 2016, a new class of alternative DOI resolvers
was started by http://doai.io. This service is unusual in
that it tries to find a non-paywalled (often author
archived) version of a title and redirects the user to that
instead of the publisher's version.[31][32]
Since then, other
open-access favoring DOI resolvers have been created,
notably https://oadoi.org/ in October
2016[33]
(later Unpaywall). While traditional DOI resolvers
solely rely on the Handle System, alternative DOI
resolvers first consult open access resources such
as BASE (Bielefeld Academic Search Engine).[31][33]

8. An alternative to HTTP proxies is to use one of a
number of add-ons and plug-ins for browsers, thereby
avoiding the conversion of the DOIs to URLs,[34]
which
depend on domain names and may be subject to
change, while still allowing the DOI to be treated as a
normal hyperlink. For example. the CNRI Handle
Extension for Firefox, enables the browser to access
Handle System handles or DOIs
like hdl:4263537/4000 or doi:10.1000/1 directly in
the Firefox browser, using the native Handle System
protocol. This plug-in can also replace references to
web-to-handle proxy servers with native resolution. A
disadvantage of this approach for publishers is that, at
least at present, most users will be encountering the
DOIs in a browser, mail reader, or other software which
does not have one of these plug-ins installed.
IDF organizational structure[edit]
The International DOI Foundation (IDF), a non-profit
organisation created in 1998, is the governance body of
the DOI system.[35]
It safeguards all intellectual property
rights relating to the DOI system, manages common
operational features, and supports the development and
promotion of the DOI system. The IDF ensures that any
improvements made to the DOI system (including
creation, maintenance, registration, resolution and
policymaking of DOI names) are available to any DOI
registrant. It also prevents third parties from imposing
additional licensing requirements beyond those of the
IDF on users of the DOI system.
The IDF is controlled by a Board elected by the
members of the Foundation, with an appointed
Managing Agent who is responsible for co-ordinating
and planning its activities. Membership is open to all
organizations with an interest in electronic publishing
and related enabling technologies. The IDF holds
annual open meetings on the topics of DOI and related
issues.
Registration agencies, appointed by the IDF, provide
services to DOI registrants: they allocate DOI prefixes,
register DOI names, and provide the necessary
infrastructure to allow registrants to declare and
maintain metadata and state data. Registration
agencies are also expected to actively promote the
widespread adoption of the DOI system, to cooperate
with the IDF in the development of the DOI system as a
whole, and to provide services on behalf of their specific
user community. A list of current RAs is maintained by

9. the International DOI Foundation. The IDF is recognized
as one of the federated registrars for the Handle System
by the DONA Foundation (of which the IDF is a board
member), and is responsible for assigning Handle
System prefixes under the top-level 10 prefix.[36]
Registration agencies generally charge a fee to assign a
new DOI name; parts of these fees are used to support
the IDF. The DOI system overall, through the IDF,
operates on a not-for-profit cost recovery basis.
Standardization[edit]
The DOI system is an international standard developed
by the International Organization for Standardization in
its technical committee on identification and description,
TC46/SC9.[37]
The Draft International Standard ISO/DIS
26324, Information and documentation – Digital Object
Identifier System met the ISO requirements for
approval. The relevant ISO Working Group later
submitted an edited version to ISO for distribution as an
FDIS (Final Draft International Standard) ballot,[38]
which
was approved by 100% of those voting in a ballot
closing on 15 November 2010.[39]
The final standard was
published on 23 April 2012.[1]
DOI is a registered URI under the info URI
scheme specified by IETF RFC 4452. info:doi/ is the
infoURI Namespace of Digital Object Identifiers.[40]
The DOI syntax is a NISO standard, first standardised in
2000, ANSI/NISO Z39.84-2005 Syntax for the Digital
Object Identifier.[41]
The maintainers of the DOI system have deliberately not
registered a DOI namespace for URNs, stating that:
URN architecture assumes a DNS-based Resolution
Discovery Service (RDS) to find the service appropriate
to the given URN scheme. However no such widely
deployed RDS schemes currently exist.... DOI is not
registered as a URN namespace, despite fulfilling all the
functional requirements, since URN registration appears
to offer no advantage to the DOI System. It requires an
additional layer of administration for defining DOI as a
URN namespace (the string urn:doi:10.1000/1 rather
than the simpler doi:10.1000/1 ) and an additional step
of unnecessary redirection to access the resolution
service, already achieved through either http proxy or
native resolution. If RDS mechanisms supporting URN
specifications become widely available, DOI will be
registered as a URN.

10. — International DOI Foundation, Factsheet: DOI System
and Internet Identifier Specifications
See also[edit]
 arXiv
 Bibcode
 DataCite
 Digital identity
 Metadata standards
 Object identifier
 ORCID
 PMID
 Publisher Item Identifier (PII)
 Permalink
 Scientific literature
 Universally unique identifier (UUID)
Notes[edit]
1. ^ Other registries are identified by other strings at the start of
the prefix. Handle names that begin with "100." are also in
use, as for example in the following citation: Hammond,
Joseph L. Jr.; Brown, James E.; Liu, Shyan-Shiang S. (May
1975). "Development of a Transmission Error Model and an
Error Control Model l". Technical Report RADC-TR-75-138.
Rome Air Development
Center. Bibcode:1975STIN...7615344H. hdl:100.2/ADA01393
9. Archived from the original on 25 May 2017.
References[edit]
1. ^ Jump up to:a b
"ISO 26324:2012(en), Information and
documentation – Digital object identifier system". ISO.
Retrieved 20 April 2016.
2. ^ "The Handle System".
3. ^ "Factsheets".
4. ^ Witten, Ian H.; Bainbridge, David & Nichols, David M.
(2010). How to Build a Digital Library (2nd ed.). Morgan
Kaufmann. pp. 352–253. ISBN 978-0-12-374857-7.
5. ^ Langston, Marc; Tyler, James (2004). "Linking to Journal
Articles in an Online Teaching Environment: The Persistent
Link, DOI, and OpenURL". The Internet and Higher
Education. 7 (1): 51–58. doi:10.1016/j.iheduc.2003.11.004.
6. ^ "How the "Digital Object Identifier" Works". BusinessWeek.
23 July 2001. Archived from the original on 2 October 2010.
Retrieved 20 April 2010. Assuming the publishers do their job
of maintaining the databases, these centralized references,
unlike current web links, should never become outdated or
broken
7. ^ Liu, Jia (2021). "Digital Object Identifier (DOI) Under the
Context of Research Data Librarianship". Journal of eScience

11. Librarianship. 10 (2): Article
e1180. doi:10.7191/jeslib.2021.1180.
8. ^ Paskin, Norman (2010), "Digital Object Identifier (DOI)
System", Encyclopedia of Library and Information
Sciences (3rd ed.), Taylor and Francis, pp. 1586–1592
9. ^ Jump up to:a b Davidson, Lloyd A.; Douglas, Kimberly
(December 1998). "Digital Object Identifiers: Promise and
problems for scholarly publishing". Journal of Electronic
Publishing. 4 (2). doi:10.3998/3336451.0004.203.
10. ^ "Welcome to the DOI System". Doi.org. 28 June 2010.
Retrieved 7 August 2010.
11. ^ "DOI News, April 2011: 1. DOI System exceeds 50 million
assigned identifiers". Doi.org. 20 April 2011. Retrieved 3
July 2011.
12. ^ "doi info & guidelines". CrossRef.org. Publishers
International Linking Association, Inc. 2013. Archived from the
original on 21 October 2002. Retrieved 10 June 2016. All DOI
prefixes begin with "10" to distinguish the DOI from other
implementations of the Handle System followed by a four-digit
number or string (the prefix can be longer if necessary).
13. ^ "Factsheet—Key Facts on Digital Object Identifier
System". doi.org. International DOI Foundation. 6 June 2016.
Retrieved 10 June 2016. Over 18,000 DOI name prefixes
within the DOI System
14. ^ "DOI Handbook—2 Numbering". doi.org. International DOI
Foundation. 1 February 2016. Retrieved 10 June 2016. 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.
15. ^ "Frequently asked questions about the DOI system: 6. What
can a DOI name be assigned to?". International DOI
Foundation. 3 July 2018 [update of earlier version].
Retrieved 19 July 2018.
16. ^ "DOI Handbook – Numbering". doi.org. 13 February 2014.
Section 2.6.1 Screen and print presentation. Archived from
the original on 30 June 2014. Retrieved 30 June 2014.
17. ^ "DOI Display Guidelines".
18. ^ "New Crossref DOI display guidelines are on the way".
19. ^ Powell, Andy (June 1998). "Resolving DOI Based URNs
Using Squid: An Experimental System at UKOLN". D-Lib
Magazine. doi:10.1045/june98-powell. ISSN 1082-9873.
20. ^ ChrissieCW. "Crossref Revises DOI Display Guidelines -
Crossref". www.crossref.org.
21. ^ "Japan Link Center(JaLC)". japanlinkcenter.org. Retrieved 6
August 2022.
22. ^ Green, T. (2009). "We Need Publishing Standards for
Datasets and Data Tables". Research
Information. doi:10.1787/603233448430.
23. ^ "multilingual European DOI Registration Agency".
mEDRA.org. 2003.
24. ^ Levine, John R. (2015). "Assigning Digital Object Identifiers
to RFCs § DOIs for
RFCs". IAB. doi:10.17487/rfc7669. RFC 7669.
25. ^ Timmer, John (6 March 2010). "DOIs and their
discontents". Ars Technica. Retrieved 5 March 2013.
26. ^ DeRisi, Susanne; Kennison, Rebecca; Twyman, Nick
(2003). "Editorial: The what and whys of DOIs". PLoS
Biology. 1 (2):
e57. doi:10.1371/journal.pbio.0000057. PMC 261894. PMID 1
4624257.

12. 27. ^ Franklin, Jack (2003). "Open access to scientific and
technical information: the state of the art". In Grüttemeier,
Herbert; Mahon, Barry (eds.). Open access to scientific and
technical information: state of the art and future trends. IOS
Press. p. 74. ISBN 978-1-58603-377-4.
28. ^ "DOI System and Internet Identifier Specifications". Doi.org.
18 May 2010. Retrieved 7 August 2010.
29. ^ "DOI System and standard identifier registries". Doi.org.
Retrieved 7 August 2010.
30. ^ International DOI Foundation (7 August
2014). "Resolution". DOI Handbook. Retrieved 19
March 2015.
31. ^ Jump up to:a b "DOAI". CAPSH (Committee for the
Accessibility of Publications in Sciences and Humanities).
Retrieved 6 August 2016.
32. ^ Schonfeld, Roger C. (3 March 2016). "Co-opting 'Official'
Channels through Infrastructures for Openness". The
Scholarly Kitchen. Retrieved 17 October 2016.
33. ^ Jump up to:a b Piwowar, Heather (25 October
2016). "Introducing oaDOI: resolve a DOI straight to OA".
Retrieved 17 March 2017.
34. ^ "DOI System Tools".
35. ^ "Chapter 7: The International DOI Foundation". DOI
Handbook. Doi.org. Retrieved 8 July 2015.
36. ^ "DONA Foundation Multi-Primary Administrators". Archived
from the original on 14 January 2017. Retrieved 7
February 2017.
37. ^ "Digital object identifier (DOI) becomes an ISO standard".
iso.org. 10 May 2012. Retrieved 10 May 2012.
38. ^ "about_the_doi.html DOI Standards and Specifications".
Doi.org. 28 June 2010. Retrieved 7 August 2010.
39. ^ "Overviews & Standards – Standards and Specifications: 1.
ISO TC46/SC9 Standards". Doi.org. 18 November 2010.
Retrieved 3 July 2011.
40. ^ "About "info" URIs – Frequently Asked Questions". Info-
uri.info. Retrieved 7 August 2010.
41. ^ "ANSI/NISO Z39.84-2005 Syntax for the Digital Object
Identifier" (PDF). National Information Standards
Organization. Retrieved 25 June 2021.
External links[edit]
Wikidata has the property:
 DOI (P356) (see uses)
 Official website
 Short DOI – DOI Foundation service for converting
long DOIs to shorter equivalents
 Factsheet: DOI System and Internet Identifier
Specifications
 CrossRef DOI lookup
hide

13. International numbering standards
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rd Musical Work Code (ISWC)
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