What is DOI?
The digital object identifier ( Eng. The Digital the Object the Identifier, abbr DOI.) - ISO standard 26324: 2012 designation of the information in the object network. In fact, DOI is a link (URL) to the permanent location of an object or information about it (metadata) on the Internet.
DOI can be assigned to any object. An object can be anything - an online publication or part of it (book, book chapter, article) or an element (figure, table, formula, etc.), audio and video content, datasets and databases, material objects (DVD, paper book).
In the Russian Federation, for the abbreviation DOI in GOST R ISO 26324-2015, the decoding "discrete object identifier" is standardized, while the essence of the term is the same as in the ISO 26324: 2012 standard
DOIs allow you to unambiguously and accurately identify an object and gain access to detailed information about it (metadata) or directly to the object itself, if access to the object is open. The organization that assigned the DOI to the object is obliged to ensure the continued operability of the link to the object and / or data about it. This means that an object that has been assigned a DOI can be found even if its location changes. Moreover, the object itself and the information associated with this object can always be added, changed or grouped in various ways and at any time by the DOI owner himself.
Using DOIs, related objects, such as versions (revisions) of an object, can also be differentiated and linked separately (see, for example, the Crossmark by Crossref scientific publication version control system).
The information contained in the DOI of an electronic document contains an indicator of its location (for example, URL ), its name (title), other object identifiers (for example, ISBN for an electronic image of a book) and a set of data (metadata) that describes it in a structured and expandable form.
The International DOI Foundation (IDF) is a membership-based not-for-profit organization that is the parent oversight and governance body for the Federation of Registration Agencies (RAs) providing end-user services for DOI prefixing, DOI registration for objects, and related DOI services.
IDF is the ISO 26324 Authorized Registrar for the DOI System.
The DOI system provides the technical and social infrastructure for the registration and use of permanent and interoperable  DOI identifiers for use in digital networks. The DOI system consists of:
Registration agencies are appointed by IDF and provide services to DOI prefix owners: they distribute DOI prefixes, register DOIs for objects and provide the necessary infrastructure to allow object owners to assign DOIs, transfer and update object metadata and their state data. Registration agencies are also expected to actively promote widespread adoption of the DOI system, partner with IDF to develop the DOI system in general, and provide services on behalf of their specific user community.
Each RA has its own clearly defined area of responsibility. For a complete list of current RAs and their areas of responsibility, see the IDF website .
Crossref is an international RA providing DOI for scientific publications (books, journal articles, conference proceedings, etc.);
Datacite - RA that provides DOI for data sets (results of experiments, calculations and calculations, indicators of devices and sensors, etc.) stored in scientific data centers, research organizations, libraries, technical and statistical information storages, etc. DOI DataCite is not intended for scientific publications, but only for data and data sets. 
Entertainment Identifier Registry (EIDR) RA providing DOIs for commercial video content.
Japan Link Center (JaLC) - An RA providing DOI for Japanese-language electronic scientific journals.
The Chinese National Knowledge Infrastructure (CNKI) is an RA providing DOI for Chinese scientific publications created with the support of the Chinese government by Xinhua University and the China Institute of Scientific and Technical Information.
Publications Office of the European Union (OP) - RA providing DOIs for official publications of European Union bodies;
Externally, DOI is a unique string of letters and numbers made up of two parts: a prefix and a suffix.
For example, 10.1000 / 182, where:
10.1000 - prefix or identifier of the owner (publisher, copyright holder, data center, library, etc.), composed of the identifier attribute (10) and a string indicating the owner (1000);
182 - suffix, object identifier indicating a specific object. The suffix is formed by the owner himself and can contain any set of numbers and / or letters at the discretion of the owner of the prefix.
However, in essence, DOI is a link (URL), a path to an object (article, book, data, etc.) in a general information-virtual space (usually on the Internet), to gain access to the object and / or the necessary information about him.
Therefore, in accordance with the requirements of Crossref, both in publications and on websites DOI must be displayed as an Internet link (URL) and the way the suffix is indicated does not matter for the link to work correctly.
DOI examples :
This DOI digital copy of the book in 2006 «the Functions of Beyond Magnetic Spin-Hamiltonian» ( the ISBN 3-540-26079-the X ), published in Berlin under the editorship of Professor D. Michael P. Mingos, entering at number 117 in the series - the magazine «Structure & Bonding ( ISSN 0081-5993 edited by D. Michael P. Mingos) by Springer-Verlag Berlin Heidelberg (as part of Springer Science + Business Media ). The book also has Library of Congress Control Number (LCCN) 2005926235.
This is the DOI of a digital copy of the 2007 book Organometalliс Chemistry & Catalysis ( ISBN 978-3-540-46129-6 ) by Didier Astruc ( IUF member [fr] ), published by Springer-Verlag Berlin Heidelberg in English . LCCN 2007924912. Originally, the contents of this book were published in 2000 in French in the book Chimie Organométallique ( ISBN 2-86883-493-0 ) by EDP Sciences [fr] Grenoble.
Every author, worried about his scientific image and the level of his citation, should think about the fact that each of his articles has a DOI. Moreover, this can be done even for archival materials, by agreement with the publishing house itself.
Contract for the provision of services for the assignment of DOI codes No DOI-18581/2020