DOI (digital identifier)


August 13, 2022

Digital object identifier (DOI) - an identifier of an electronic document, which, unlike URL identifiers, does not depend on the physical location of the document, but is permanently assigned to it. The creator of this system and the owner of the DOI trademark is the International DOI Foundation. This institution defines DOI as: a digital identifier for any intellectual property object whose task is to permanently identify any intellectual property object on digital networks in relation to up-to-date data on it. A typical application of DOI is to identify electronic versions of scientific publications. Knowing the DOI number of a publication, using special databases, you can easily find a place on the Internet from where the publication can be downloaded at the moment. However, a DOI number can also be obtained, for example, by an entire scientific journal, a chapter in a book, a multimedia file or a computer program. DOI uses a standard developed by CNRI called the Handle System, which allows for assigning any object a unique identifier, correlated with an entry in the database about this object. DOI identifiers were given the prefix 10 as part of the Handle System.

DOI format

DOIs are ASCII strings. They consist of two parts: the prefix and the ending. Example: 10.1000 / 182 where: 10.1000 is the prefix where the 10 characters indicate that it is a DOI identifier, and .1000 is the number assigned to the publisher (Publisher ID) 182 is the ending that is assigned to a specific item (Item ID). The prefix and ending length can be any length, and in addition to numbers, they can also contain other ASCII characters. A Publisher ID is assigned to publishers who have chosen to register and use the DOI system by one of the agencies authorized to do so. Item ID - is given by the publisher themselves, who must guarantee that it will be unique for each work they publish. The Item ID may or may not be a work catalog number from other registration systems, such as an ISBN, ISSN, or a publisher's internal catalog number.

Metadata and access to it

The DOI system, in addition to registering and collecting the identifiers, also allows publishers to add a lot of additional information to the database, such as the current URL where you can find a copy of the work, information about the authors, price, availability, release date, short description of the content of the work, etc. Publishers using the system can change and update the metadata of their published works at any time. This data is publicly available and can therefore be used to build a variety of secondary databases from which a variety of services can be offered. For example, an online bookstore can easily use DOI metadata to automatically update the prices and availability of the e-books it offers. The DOI system allows you to easily find the metadata assigned to a specific identifier, which is called "decoding" it. The 'decryption' of DOI identifiers is possible via an internet service offered to the public and free of charge by the Handle System. The URL for a given DOI (for example for 10.1000 / 182) looks like or (deprecated). URLs created in this way can be used as links to target objects on websites. This way, you can check that the example DOI: 10.1000 / 182 points to the Travel description