In this paper, I link philosophical discussion of policies for trans inclusion or exclusion, to a method of policy making. I address the relationship between concerns about safety, fairness, and inclusion in policy making about the inclusion of transwomen athletes into women’s sport. I argue for an approach based on lexical priority rather than simple ‘balancing’, considering the different values in a specific order. I present justifying reasons for this approach and this lexical order, based on the special obligations of (...) International Federations such as World Rugby. As a result, I provide a justificatory framework for the WR Guidelines that exclude transwomen from the women’s game in WR competitions. Finally, I give an account of a maximally safe, maximally fair and maximally inclusive form of sex categorisation in sport. (shrink)