The Oxford Common File Layout describes a shared approach to filesystem layouts for institutional and preservation repositories, providing recommendations for how digital repository systems should structure and store files on disk or in object stores. The authors represent institutions where digital preservation practices have been established and proven over time or where significant work has been done to flesh out digital preservation practices. A community of practitioners is surfacing and is assessing successful preservation approaches designed to address a spectrum of use cases. With this context as a background, the Oxford Common File Layout (OCFL) will be described as the culmination of over two decades of experience with existing standards and practices.