The Plan S Rights Retention Strategy is an administrative and legal burden, not a sustainable open access solution

to inform publishers that the author accepted manuscript (AAM) will be made available under a Creative Commons Attribution (CC BY) licence. The laudable stated aim of the RRS is to achieve immediate open access to research outputs, while preserving journal choice for authors. However, proponents of the RRS overlook the significant administrative and legal burdens that the RRS places on authors and readers. Even though compliance with existing green open access (self-archiving) policies is poor at best, the RRS is likely to rely on authors to successfully execute the CC licensing of their work in the face of publisher resistance. The complexity of copyright law and CC licensing gives many reasons to doubt the legal validity of an RRS licence grant, which creates legal risk for authors and their institutions. The complexity of RRS CC BY licensing also creates legal risk for readers, who may not be able to fully rely on the reuse rights of a CC BY licence on the AAM. However, cOAlition S has released no legal advice that explains why the RRS is valid and legally binding. Publishers of legacy subscription journals have already begun implementing strategies that ensure they can protect their revenue streams. These actions may leave authors having to choose between paying publication fees and complying with their funding agreements. The result is that the RRS increases the complexity of the copyright and licensing landscape in academic publishing, creates legal risk and may not avoid author fees. Unless increased complexity and conflict between authors and publishers drives open access, the RRS is not fit for its stated purpose as an open access strategy. The Plan S Rights Retention Strategy is an administrative and legal burden, not a sustainable open access solution