OpenCitations and the Initiative for Open Citations: A Clarification

Some folk are confused, but OpenCitations and the Initiative for Open Citations, despite the similarity of their names, are two distinct organizations.

OpenCitations ( is an open scholarly infrastructure organization directed by Silvio Peroni and myself, and its primary purpose is to host and build the OpenCitations Corpus (OCC), an RDF database of scholarly citation data that now contains almost 13 million citation links.

In contrast, the Initiative for Open Citations (I4OC; is a separate and independent organization, whose founding was spearheaded by Dario Taraborelli of the WikiMedia Foundation.  OpenCitations was just one of several organizations that founded the Initiative for Open Citations, as documented at

I4OC is a collaboration between scholarly publishers, researchers, and other interested parties to promote the unrestricted availability of scholarly citation data, but it does not itself host citation data.

Within a short space of time, I4OC has persuaded most of the major scholarly publishers to open their reference lists submitted to Crossref, so that the proportion of all references submitted to Crossref that are now open has risen from 1% to over 50%.

These references are now available for OpenCitations to harvest into the OpenCitations Corpus and publish in RDF, as well as for others to harvest and use as they wish.

All clear now?

Cite this article as: davidshotton, "OpenCitations and the Initiative for Open Citations: A Clarification," in OpenCitations blog, 29/01/2018,

Oxford University Press opens its references!

Good news!  Today, on January 16th 2018, Oxford University Press (OUP) announced its participation in the Initiative for Open Citations, and requested Crossref to turn on reference sharing for all OUP deposited references from more than half a million publications.  Oxford University Press is the largest university press in the world, publishing in 70 languages and 190 countries.

OUP logo

Their announcement is at

OUP now joins the elite band of four university presses that have already made their references open at Crossref in response to the I4OC call (

This decision by OUP has been a long time in gestation – see my 2012 post Oxford University Press to support Open Citations – but is no less welcome for that!

Cite this article as: davidshotton, "Oxford University Press opens its references!," in OpenCitations blog, 16/01/2018,

Funders should mandate open citations

On 9th January 2018, I published a World View article in Nature entitled Funders should mandate open citations [1], in which I argue that access to open references from scholarly publications is so important that, when encouragements from organisations such as the Initiative for Open Citations (I4OC) to publishers to open their references fall on deaf ears, then sterner measures are required.

Where sterner measures . .

Specifically, major funders should extend their open access mandates and require grant recipients to publish only in journals whose publishers ensure their references are open.

This suggestion was originally made by Catriona MacCallum, Director of Open Science at Hindawi, during a recent I4OC conference call, and she deserves the credit for it.

My article is freely available from Nature:

online at; PDF at

[1]        David Shotton (2018).  Funders should mandate open citations.  Nature 553: 129.               doi:10.1038/d41586-018-00104-7

Cite this article as: davidshotton, "Funders should mandate open citations," in OpenCitations blog, 15/01/2018,


Barriers to comprehensive reference availability

Two significant barriers prevent comprehensive reference availability through Crossref.

The first barrier

First, two-thirds of Crossref’s publisher-members, in particular the smaller ones, do not submit references along with the other details of their publications. Many of these published works are of types (e.g. abstracts, editorials and news items) that lack any references.  However, while the number of non-submitted references associated with other publications from these publishers is not known, it is likely to be substantial.

Ironically, quite a number of publishers have their Crossref reference status option set to ‘Open’, and yet fail to submit any references!

All publishers who use Crossref DOIs and submit metadata describing their works to Crossref should be strongly encouraged to start submitting associated reference lists if these exist.  Crossref have confirmed that it is easy to do, with or without membership of Crossref’s free and beneficial Cited-by Service that provides publishers with statistics on the citations of their own publications.  Help can be provided by Crossref Support (

The second barrier

The second barrier to full reference availability is created by publishers that submit references to Crossref, but do not presently make them open. Elsevier is by far the largest member of this group, which also includes the American Chemical Society, IEEE and Wolters Kluwer Health.

It is both quick and easy for a publisher to change its preference setting and request that all the references associated with its DOI prefixes are made open – all it requires is an email request to  But without such a request, the references will be remain in the default ‘Limited’ status.

References that are not associated with Crossref

There are, of course, many scholarly publications, for example preprints in repositories such as arXiv, and journal articles and monographs from small academic publishers in the Humanities, that do not have Digital Object Identifiers issued by Crossref.  There are also an increasing number of datasets in repositories such as Dryad that have associated references to the scholarly literature, but whose DOIs are issued by DataCite.  None of these submit references to Crossref where they can be made available via the Crossref API, and separate additional measures will be required to capture and share their references with the community.

Cite this article as: davidshotton, "Barriers to comprehensive reference availability," in OpenCitations blog, 09/01/2018,





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