In REF 2021, 98% of submitted outputs were journal articles or books. But REF 2028 will assess a project’s “contribution to knowledge and understanding” rather than its formal publications and how findings are communicated to non-researchers, such as policy makers and the public. Hidden Ref, launched in 2019, is inviting universities to sign a 5% Manifesto for REF 2028 that commits them to submitting at least 5% of their contributions in forms other than journal articles or books. Join us to discuss what a ”contribution to knowledge and understanding” means. Will your institution sign up to the 5% Manifesto?