  HEFCE's Policy for open access in the post-2014 Research Excellence Framework
states "authors' outputs must have been deposited in an institutional or
subject repository". There is no definition of a subject repository in the
policy: however, there is a footnote stating: "Individuals depositing their
outputs in a subject repository are advised to ensure that their chosen
repository meets the requirements set out in this policy." The longest standing
subject repository (or repository of any kind) is arXiv.org, established in
1991. arXiv is an open access repository of scientific research available to
authors and researchers worldwide and acts as a scholarly communications forum
informed and guided by scientists. Content held on arXiv is free to the end
user and researchers can deposit their content freely. As of April 2018, arXiv
held over 1,377,000 eprints. In some disciplines arXiv is considered essential
to the sharing and publication of research. The HEFCE requirements on
repositories are defined in the Information and Audit Requirements which lists
the "Accepted date", the "Version of deposited file" and "available open access
immediately after the publisher embargo" are expected as part of the REF
submission. However, while many records in arXiv have multiple versions of
work, the Author's Accepted Manuscript is not identified and there is no field
to record the acceptance date of the work. Because arXiv does not capture these
two specific information points it does not meet the technical requirements to
be a compliant subject repository for the purposes of REF. This paper is
presenting the case that articles deposited to arXiv are, in general, compliant
with the requirements of the HEFCE policy. The paper summarises some work
undertaken by Jisc to establish if there are other factors that can indicate
the likelihood of formal compliance to the HEFCE policy.
