Plan S currently applies only to peer-reviewed scholarly articles. cOAlition S strongly encourages, but does not currently require, that research data and other research outputs are made as open as possible and as closed as necessary. It is understood that the timeline to achieve Open Access for monographs and book chapters will be longer and requires a separate and due process. cOAlition S will, by the end of 2021, issue a statement on Plan S principles as they apply to monographs and book chapters, together with related implementation guidance. It is expected that how and whether Plan S applies to different forms of monograph or books, such as trade books, will be considered as part of the future guidance.