cOAlition S is an international consortium of research funding and performing organisations who are committed to making full and immediate Open Access to research publications a reality. cOAlition S has developed Plan S whereby research funders will mandate that access to research publications that are generated through research grants that they allocate, must be free to access on the day of publication. In addition, the right to reuse the article is subject to a special type of open licence (usually the Creative Commons Attribution licence (CC-BY)) that grants the reader the right to reuse all or parts of it without having to seek additional permission, subject to appropriate attribution of the original source. See cOAlition S website. For one definition of open access see the Berlin Declaration at openaccess.mpg.de/Berlin-Declaration