</p>

<p>
Type unification is controlled by a <i>matching mode</i>, which may
be <i>exact</i> or <i>loose</i>.
As unification recursively descends a composite type structure,
the matching mode used for elements of the type, the <i>element matching mode</i>,
remains the same as the matching mode except when two types are unified for

## Other notable changes
### API Machinery

- kube-apiserver: the `--runtime-config` flag now supports an `api/beta=false` value which disables all built-in REST API versions matching `v[0-9]+beta[0-9]+`. ([#84304](https://github.com/kubernetes/kubernetes/pull/84304), [@liggitt](https://github.com/liggitt))

 - Kubeadm: remove the automatic detection and matching of cgroup drivers for Docker. For new clusters if you have not configured the cgroup driver explicitly you might get a failure in the `kubelet` on driver mismatch (kubeadm clusters should be using the `systemd` driver). Also remove the `IsDockerSystemdCheck`...

- Introduced support for using an implicit extended resource name derived from the device class (`deviceclass.resource.kubernetes.io/<device-class-name>`) to request DRA devices matching that class. ([#133363](https://github.com/kubernetes/kubernetes/pull/133363), [@yliaog](https://github.com/yliaog)) [SIG Node, Scheduling and Testing]

* kubectl port-forward now allows using resource name (e.g., deployment/www) to select a matching pod, as well as the use of --pod-running-timeout to wait until at least one pod is running. ([#59705](https://github.com/kubernetes/kubernetes/pull/59705), [@phsiao](https://github.com/phsiao))

- Added CEL runtime cost calculation into ValidatingAdmissionPolicy, matching the evaluation cost
  restrictions that already apply to CustomResourceDefinition.
  If rule evaluation uses more compute than the limit, the API server aborts the evaluation and the

- kube-apiserver: When using `--enable-admission-plugins` the `Priority` admission plugin is now enabled by default (matching changes in 1.11.1+). If using `--admission-control` to fully specify the set of admission plugins, it is now necessary to add the `Priority` admission plugin for the PodPriority feature to work properly. ([#65739](https://github.com/kubernetes/k...

#### Cluster Selection
* [alpha] Federation [ClusterSelector annotation](https://kubernetes.io/docs/tasks/administer-federation/cluster/#clusterselector-annotation) to direct objects to federated clusters with matching labels.


### **Instrumentation**
#### Core Metrics API

- The calculations for Pod topology spread skew now exclude nodes that
  don't match the node affinity/selector. This may lead to unschedulable pods if you previously had pods
  matching the spreading selector on those excluded nodes (not matching the node affinity/selector),
  especially when the `topologyKey` is not node-level. Revisit the node affinity and/or pod selector in the

* Advanced audit now correctly reports impersonated user info. ([#48184](https://github.com/kubernetes/kubernetes/pull/48184), [@CaoShuFeng](https://github.com/CaoShuFeng))