Does they K8S repo have a branching and release policy?

I am doing an article on branching and release policies for the more popular open-source projects. Kubernetes is a significant project. Thus, my interest.

Tell me please, do you have have a branching and release policy/pattern that I can read? Or is it a matter of convention and tribal knowledge? If so, what is the policy/pattern?

Thanks in advance,
Bob Reselman