- Added driver-owned fields in `ResourceSlice` to mark whether the device was shareable among multiple resource claims (or requests) and to specify how each capacity could be shared between different requests.
  - Added user-owned fields in `ResourceClaim` to specify resource requirements against each device capacity.

- CRDs can have fields named `type` with value `array` and nested array with `items` fields without validation to fall over this. ([#85223](https://github.com/kubernetes/kubernetes/pull/85223), [@sttts](https://github.com/sttts))

### Apps

- Fixed a bug that prevents kubectl to validate CRDs with schema using x-kubernetes-preserve-unknown-fields on object fields.
  Fix kubectl SchemaError on CRDs with schema using x-kubernetes-preserve-unknown-fields on array types. ([#96563](https://github.com/kubernetes/kubernetes/pull/96563), [@gautierdelorme](https://github.com/gautierdelorme)) [SIG API Machinery and Testing]

  - [Important Security Information](#important-security-information-1)
    - [CVE-2021-25735: Validating Admission Webhook does not observe some previous fields](#cve-2021-25735-validating-admission-webhook-does-not-observe-some-previous-fields)
  - [Changes by Kind](#changes-by-kind-9)
    - [API Change](#api-change-2)
    - [Feature](#feature-5)
    - [Bug or Regression](#bug-or-regression-9)

- kube-apiserver `--egress-selector-config-file` files were validated strictly (EnableStrict). Duplicate and unknown fields in the configuration will now cause an error. ([#128011](https://github.com/kubernetes/kubernetes/pull/128011),...

  If the `DeclarativeValidation` feature gate is enabled, mismatches with existing validation are reported via metrics.

* Node affinity has moved from annotations to api fields in the pod spec.  Node affinity that is defined in the annotations will be ignored. ([#37299](https://github.com/kubernetes/kubernetes/pull/37299), [@rrati](https://github.com/rrati))

- The `kubectl diff` changed to ignore managed fields by default, and a new --show-managed-fields flag has been added to allow you to include managed fields in the diff. ([#111319](https://github.com/kubernetes/kubernetes/pull/111319), [@brianpursley](https://github.com/brianpursley))

  - The schema for the alpha `CSINodeInfo` CRD has been split into `spec` and `status` fields, and new fields `status.available` and `status.volumePluginMechanism` added. Clusters using the previous alpha schema must delete and recreate the CRD using the new schema. ([#70515](https://github.com/kubernetes/kubernetes/pull/70515), [@davidz627](http...

 * kubeadm: The Token-related fields in the `MasterConfiguration` object have now been refactored. Instead of the top-level `.Token`, `.TokenTTL`, `.TokenUsages`, `.TokenGroups` fields, there is now a `BootstrapTokens` slice of `BootstrapToken` objects that support the same features under the `.Token`, `.TTL`, `.Usages`, `.Groups` fields. ([#64408](https://github.com/kubernetes/kubernetes/pull/64408), [@luxas](https://github.com/luxas))...