* Because some plugins mount volume on sub-directory of volume path, we need to distinguish between volume path and mount path to fix issue in reconstruction. ([#74653](https://github.com/kubernetes/kubernetes/pull/74653), [@cofyc](https://github.com/cofyc))

* API fields that previously serialized null arrays as `null` and empty arrays as `[]` no longer distinguish between those values and always output `[]` when serializing to JSON. ([#43422](https://github.com/kubernetes/kubernetes/pull/43422), [@liggitt](https://github.com/liggitt))

}

// ReplicationControllerSpec is the specification of a replication controller.
message ReplicationControllerSpec {
  // Replicas is the number of desired replicas.
  // This is a pointer to distinguish between explicit zero and unspecified.
  // Defaults to 1.
  // More info: https://kubernetes.io/docs/concepts/workloads/controllers/replicationcontroller#what-is-a-replicationcontroller
  // +optional

- The `kubectl wait --for=delete` command now ignores the not found error correctly. ([#96702](https://github.com/kubernetes/kubernetes/pull/96702), [@lingsamuel](https://github.com/lingsamuel))

- Change plugin name in fsgroupapplymetrics of csi and flexvolume to distinguish different driver ([#95892](https://github.com/kubernetes/kubernetes/pull/95892), [@JornShen](https://github.com/JornShen)) [SIG Instrumentation, Storage and Testing]

- Certificate handling improvements:
  - Renew certs as part of upgrade.
  - New `kubeadm alpha phase certs renew` command for renewing certificates.
  - Certificates created with kubeadm now have improved uniqueness of Distinguished Name fields.
- HA improvements:
  - `kubeadm join --experimental-control-plane` can now be used to join control plane instances to an existing cluster.

* Protobuf serialization does not distinguish between `[]` and `null`.
API fields previously capable of storing and returning either `[]` and `null` via JSON API requests (for example, the Endpoints `subsets` field)

        <match value="0x0001" type="big16" offset="10"/>
      </match>
    </magic>
  </mime-type>
  <mime-type type="application/vnd.wordperfect;version=6.x">
    <!--TODO: figure out how to distinguish 6.x versions -->
    <sub-class-of type="application/vnd.wordperfect"/>
    <magic priority="50">
      <match value="0xFF575043" type="big32" offset="0"> <!-- ÿWPC -->

* Protobuf serialization does not distinguish between `[]` and `null`. ([#45294](https://github.com/kubernetes/kubernetes/pull/45294), [@liggitt](https://github.com/liggitt))

* Protobuf serialization does not distinguish between `[]` and `null`. ([#45294](https://github.com/kubernetes/kubernetes/pull/45294), [@liggitt](https://github.com/liggitt))