DOI - The ID Card of any Scientific Publication: 2. Numbering

Image credit: Wikipedia

The DOI  Number

Each DOI is a unique string of numbers, letters, and symbols. The uniqueness is ensured by the DOI system, which is based on the Handle system.  The character string consists of two parts - prefix and suffix. This syntax is standardized by the International Organization for Standardization (ISO).

The Handle System

The Handle System is a "rapid-resolution, globally distributed system run by multiple groups that the public can use for resolving identifiers (handles)" []. The system was developed by Dr. Robert Kahn - Chairman, CEO, and President of the Corporation for National Research Initiatives (CNRI).  It was implemented for the first time in the second half of 1994. Since 2015 it is administered by the DONA Foundation which gives accreditation to the so-called "Multi-Primary Administrators" or MPAs. One of them is the International DOI Foundation. Each Handle consists of a prefix - an identifier of the authority giving the DOI, and a suffix - the unique "name" of the content. The Handle encodes no information about the content, but only provides the means to retrieve the metadata of the content.

The Syntax of a DOI

As DOI is in fact a Handle system handle, it also consists of a prefix and a suffix separated by slash "/". The length is not limited and any Unicode symbol can be used (the DOI is case in-sensitive). To resolve a DOI name one needs a DOI resolver (eg. 

Image credit: ITU

- Prefix - The DOI prefix consists of a directory indicator and a registrant code separated by a full stop "." The directory indicator is always "10" and defines a handle as Digital Object Identifier. The registrant code is a unique string assigned to each registrant. By adding a full stop "." at the end of the registrant code and a new number, the registrant code can be assigned sub-categories, which are not hierarchically subordinated but have equal status with any registrant code.

- Suffix - The suffix is created and assigned by the registrant. It has an unlimited length and should be unique for the specific prefix. 

A DOI can be assigned to any entity or a part of it - for example, there can be a DOI for a book of conference proceedings and then each paper in the book can have its own DOI. As sometimes the DOI names are actually very long strings, there is a public service called short DOI that creates shortcuts to DOI names in the form of 10/*******. Those are not unique DOIs but shortcuts to DOIs that already exist.

As in the modern world, more and more content is both digital and printed, often there is a requirement for the DOI to be put also on the printed material.

On this date, 543 years ago...
Friday Inspirational quotes: Carl Gustav Jung

Related Posts



No comments made yet. Be the first to submit a comment
Already Registered? Login Here
Monday, 29 November 2021

Captcha Image

By accepting you will be accessing a service provided by a third-party external to