PLAN S

The prevailing system of scholarly publishing kept some publicly and privately funded research outputs behind subscription barriers and embargo periods, limiting access and reuse. In this context, Plan S was launched in 2018 to accelerate the transition towards immediate open access to peer-reviewed scientific publications resulting from research funded by members of cOAlition S. The revised 2019 formulation states that, as a minimum, its principles were to apply to calls or application deadlines published from 1 January 2021 onwards (cOAlition S, 2019).

Its central objective is for these publications to be available without any embargo period, either in open access journals or platforms or through immediate deposit in repositories, with open licences (preferably CC BY) and with copyright retained by authors or institutions. This objective is set out in 10 principles that turn these commitments into verifiable requirements: common criteria for journals, platforms and repositories; support for open access infrastructures; institutional or funder coverage of publication fees where they exist; cost transparency requirements; restriction of the hybrid model outside transformative agreements; and assessment based on the intrinsic merit of the work rather than on the prestige of the journal or its impact factor (cOAlition S, 2019).

Implementation is structured through routes to compliance and funding conditions. The implementation guidance recognises as valid routes publication in open access journals or platforms, immediate deposit in repositories when publishing in subscription journals and, transitionally, open publication under transformative agreements. In addition, funders were expected to align their grant agreements and funding conditions with these requirements and to provide monitoring and sanction mechanisms in cases of non-compliance (cOAlition S, 2019).