- Improved how the API server responds to **list** requests where the response format negotiates to Protobuf. List responses in Protobuf are marshalled one element at the time, drastically reducing memory needed to serve large collections. Streaming list responses can be disabled via the `StreamingCollectionEncodingToProtobuf` feature gate....

- Client-go: Clients can request protobuf and json and correctly negotiate with the server for JSON for CRD objects, allowing all client libraries to request protobuf if it is available.  If an error occurs negotiating a watch with the server, the error is immediately return by the client `Watch()` method instead of being...

- Fixes wrong validation result of NetworkPolicy PolicyTypes ([#85747](https://github.com/kubernetes/kubernetes/pull/85747), [@tnqn](https://github.com/tnqn)) [SIG Network]
- For subprotocol negotiation, both client and server protocol is required now. ([#86646](https://github.com/kubernetes/kubernetes/pull/86646), [@tedyu](https://github.com/tedyu)) [SIG API Machinery and Node]

- Changed the API server so that for admission webhooks that have a URL matching the hostname 'localhost' or a loopback IP address, the connection supports HTTP/2 where it could be negotiated.
   ([#122558](https://github.com/kubernetes/kubernetes/pull/122558), [@linxiulei](https://github.com/linxiulei))

*   You can now use a new supported service annotation for AWS clusters, `service.beta.kubernetes.io/aws-load-balancer-ssl-negotiation-policy`, which lets you specify which [predefined AWS SSL policy](http://docs.aws.amazon.com/elasticloadbalancing/latest/classic/elb-security-policy-table.html) you would like to use. ([#54507](https://github.com/kubernetes/kubernetes/pull/54507),[...