PKP has developed a Private LOCKSS Network (PLN) to digitally preserve OJS journals. The LOCKSS program offers decentralized and distributed preservation, seamless perpetual access, and preservation of the authentic original version of the content. The PKP PLN ensures that journals that are not part of the Global LOCKSS Network, which primarily preserves content from larger publishers and vendors, or an existing PLN, which preserve small numbers of OJS journals hosted by member libraries, can be preserved using the LOCKSS program. For additional details about the PKP PLN, see the high level overview (an early discussion document).

With the release of OJS 2.4.8, the PKP PLN is now open to the OJS user community!
Join the PLN



  • provides preservation services for any OJS journal that has published at least one article and has an ISSN and is running OJS version 2.4.8 or higher
  • allows OJS journal managers to register their journals for inclusion in the PLN by simply enabling a plugin in their OJS instance and agreeing to the terms of the Preservation Agreement
  • on registration of a journal, automatically determines if the registered journal meets the minimum inclusion requirements
  • preserves the raw journal content as generated by OJS’s existing export tools
  • automatically harvests new content from registered journals and adds the content to the PLN, eliminating manual staff intervention at PLN member sites
  • provides access to preserved content after a “trigger event”

End-user access to journals in the PKP PLN

The PKP PLN is a dark archive. End users will not have access to the preserved content until after a “trigger event.” After a trigger event, PKP staff will approve the importing of the preserved content into one or more OJS instances hosted by PKP member institutions. Once loaded into these host OJS instances, the content will be openly accessible.

Trigger events in the PKP PLN

Preserved content in the PKP PLN is only made available to users after a trigger event, at which time the content will be made accessible to the reading public. The PKP PLN defines two types of trigger events.

  1. Explicit notification by OJS Journal Manager
  2. Cessation of deposits into the PLN (after a period of inactivity)

The PKP PLN will employ automated techniques to detect a potential trigger event and contact the journal to confirm their publication status.

Preservation agreement (Journal terms)

Journal managers who would like their journal to be included in the PKP PLN need to accept the Journal Terms via the LOCKSS OJS plugin. This agreement describes what is being preserved, the nature of the PKP’s commitment to preserve their journal, PKP’s right to preserve the journal, that the content will be made accessible after a trigger event (as described above), and how they should contact the PKP to initiate a trigger event. After a trigger event, PKP intends to make content accessible via a special OJS instance that will be operated by the PLN.

*See below for journal terms.


A new LOCKSS OJS plugin is included with OJS 2.4.8 and above. The older LOCKSS OJS plugin that generates a LOCKSS manifest and permission statement will continue to work for those journals that are part of existing PLNs or the LOCKSS GLN, but will not work within the proposed PKP PLN. Journal managers can opt into the PKP PLN by activating the new plugin. (Additional LOCKSS-based solutions for OJS content are described on the LOCKSS website.)

PKP PLN nodes

PKP members who are participating in the PLN by hosting a preservation node:

  • University of Alberta
  • University of British Columbia
  • Indiana University
  • University of Pittsburgh
  • University of Victoria
  • Simon Fraser University
  • Ontario Council of University Libraries (OCUL), Scholars Portal
  • Ghent University Library
  • Italian National Library of Florence

In addition, PKP is working with other potential preservation nodes and PLNs around the world to provide further redundancy and geographical distribution within the PKP PLN.

pkpplnnodes (2)

PKP PLN Advisory Panel Members

  • Lars Bjornshauge, Directory of Open Access Journals (DOAJ)
  • Sioux Cumming, International Network for the Availability of Scientific Publications (INASP)
  • Alan Darnell, Ontario Council of University Libraries (OCUL)
  • Geoff Harder, University of Alberta Libraries
  • Sarah Lippincott, Library Publishing Coalition (LPC)
  • Alex Mendonça, SciELO
  • Susan Murray, African Journals Online (AJOL)
  • Victoria Reich, LOCKSS
  • Heather Joseph, SPARC
  • Dwayne K. Buttler, J.D., University of Louisville

Joining the PLN

All journals can join the PLN provided they meet the following criteria:

  • The journal must be running OJS 2.4.8 or higher
  • The journal must have an ISSN
  • The journal must have published at least one article

If your journal meets these criteria, you can have it preserved in the PKP PLN by accepting the Terms of Use.

To join, log in as Journal Manager and go to Journal Management > System Plugins > Generic Plugins > PKP PLN Plugin > Settings and accept the Terms of Use.

Your journal’s content (retrospective and new) will be automatically added to the PLN after you have agreed to the Journal Terms. You will not need to take any further action. The only exception is that if the terms of use  change in the future, you will be asked to re-confirm your acceptance. In this situation, OJS will provide a notification to visit the PKP PLN plugin’s administration page so you can agree to the updated Journal  Terms.


For any support issues, please post on our PKP Community Forum.

* Journal terms

As Primary Contact I, in good faith, accept and confirm the following terms and conditions for participation in the Public Knowledge Project’s Private LOCKSS Network (PKP-PLN):

  1. I have the authority to include this journal’s content in a secure preservation network and, if and when necessary, to make the content accessible in the PKP PLN and its successors.
  2. I agree to allow the PKP-PLN to include this journal’s title and ISSN, and the email address of the Primary Contact, with the preserved journal content.
  3. I confirm that licensing information pertaining to articles in this journal is accurate at the time of publication.
  4. I acknowledge these terms may be revised from time to time and will supersede all previous versions.  I will be asked to review them and to agree to them in order to continue to include this journal’s content in the PKP-PLN.
  5. I agree not to violate any laws and regulations that may be applicable to the content.
  6. I agree to make every reasonable effort to inform the PKP-PLN in the event this journal ceases publication.  I acknowledge that PKP-PLN will also employ automated techniques to detect a potential trigger event and contact the journal to confirm their publication status.
  7. I agree that the PKP-PLN reserves the right, not to preserve or make content accessible.
  8. PKP reserves the right to use the aggregated content in the PKP-PLN for research and reporting purposes and will adhere to the norms of standard research procedures.