- The `DeclarativeValidation` feature gate is enabled by default. When enabled, mismatches with existing hand written validation is reported via metrics.

- Introduced the `admissionregistration.k8s.io/v1beta1/MutatingAdmissionPolicy` API type. To enable, enable the `MutatingAdmissionPolicy` feature gate (which was off by default) and set `--runtime-config=admissionregistration.k8s.io/v1beta1=true` on the kube-apiserver. 

  Please see [the KEP](https://github.com/kubernetes/enhancements/tree/master/keps/sig-storage/1710-selinux-relabeling#story-3-cluster-upgrade) how we expect to warn users before any SELinux behavior changes and how they can opt-out before. Note that this field and feature gate is useful only with clusters that run with SELinux enabled. No action is required on clusters without SELinux. ...

  Enabling this feature will modify all Pod Security Standard rules to allow setting: `spec[.*].securityContext.[runAsNonRoot,runAsUser]`.
  This feature gate should only be enabled if all nodes in the cluster support the user namespace feature and have it enabled.

* Use inline func to ensure unlock is executed ([#61644](https://github.com/kubernetes/kubernetes/pull/61644), [@resouer](https://github.com/resouer))
* Introduce truncating audit backend that can be enabled by passing --audit-log-truncate-enabled or --audit-webhook-truncate-enabled flag to the apiserver to limit the size of individual audit events and batches of events. ([#64024](https://github.com/kubernetes/kubernetes/pull/64024), [@loburm](https://github.com/loburm))

- Overall, enable the feature of `PreferNominatedNode` will  improve the performance of scheduling where preemption might frequently happen, but in theory, enable the feature of `PreferNominatedNode`, the pod might not be scheduled to the best candidate node...

- PersistentVolumeLastPhaseTransitionTime feature is stable and enabled by default. ([#124969](https://github.com/kubernetes/kubernetes/pull/124969), [@RomanBednar](https://github.com/RomanBednar)) [SIG API Machinery, Apps, Storage and Testing]

* Existing PVs are converted to use volume topology if migration is enabled. ([#83394](https://github.com/kubernetes/kubernetes/pull/83394), [@bertinatto](https://github.com/bertinatto))

- Enabled the `StatefulSetStartOrdinal` feature gate in beta ([#115260](https://github.com/kubernetes/kubernetes/pull/115260), [@pwschuurman](https://github.com/pwschuurman))
- Enabled usage of `kube-proxy`, `kube-scheduler` and `kubelet` HTTP APIs for changing the logging

- Contextual logging is now in beta and enabled by default. Check out the [KEP](https://github.com/kubernetes/enhancements/issues/3077) and [official documentation](https://kubernetes.io/docs/concepts/cluster-administration/system-logs/#contextual-logging) for more details. ([#122589](https://github.com/kubernetes/kubernetes/pull/122589), [@pohly](https://github.com/pohly))