The `apiextensions.k8s.io/v1beta1` version of `CustomResourceDefinition` is deprecated and will no longer be served in v1.19. ([#79604](https://github.com/kubernetes/kubernetes/pull/79604), [@liggitt](https://github.com/liggitt))

- Introduced OpenAPI format support for `k8s-short-name` and `k8s-long-name` in CustomResourceDefinition schemas. ([#132504](https://github.com/kubernetes/kubernetes/pull/132504), [@jpbetz](https://github.com/jpbetz)) [SIG API Machinery, Architecture, Auth, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation, Network, Node, Scheduling and...

- Alpha support for field selectors on custom resources has been added. With the `CustomResourceFieldSelectors` feature gate enabled, the CustomResourceDefinition API now allows specifying `selectableFields`. Listing a field there enables filtering custom resources for that CustomResourceDefinition in list or watch requests. ([#122717](https://github.com/kubernetes/kubernetes/pull/122717), [@jpbetz](https://github.com/jpbetz))

### API Change

- CustomResourceDefinition objects created with non-empty `caBundle` fields which are invalid or do not contain any certificates will not appear in discovery or serve endpoints until a valid `caBundle` is provided. Updates to CustomResourceDefinition are no longer allowed to transition a valid `caBundle` field to an invalid `caBundle` field, because this breaks serving of the...

- Fix CustomResourceDefinition status.storedVersions validation error messages. ([#119653](https://github.com/kubernetes/kubernetes/pull/119653), [@sttts](https://github.com/sttts)) [SIG API Machinery]