In 2018, as part of Python's governance transition from a BDFL model with Guido van Rossum at the helm to the project's current governance, Barry Warsaw, Łukasz Langa, Antoine Pitrou, Doug Hellmann and Carol Willing submitted PEP 8002.
This PEP is a detailed overview of the governance structures of other open source projects, specifically Rust, OpenStack, Jupyter, Django, TypeScript, AstroPy and Microsoft (Microsoft is, obviously, not an open source project, but was included as a helpful counterexample.)
This PEP is a helpful guide for larger projects looking to formalize or transition their governance. Smaller projects will likely find the structures described "too much".