// optional specify whether the ConfigMap or its keys must be defined
  // +optional
  optional bool optional = 4;
}

// Adapts a ConfigMap into a volume.
//
// The contents of the target ConfigMap's Data field will be presented in a
// volume as files using the keys in the Data field as the file names, unless
// the items element is populated with specific mappings of keys to paths.

#### Storage

* [stable] Mount options

  * The ability to specify mount options for volumes is moved from beta to stable.

  * A new `MountOptions` field in the `PersistentVolume` spec is available to specify mount options. This field replaces an annotation.

- IngressClass resource can now reference a resource in a specific namespace 
  for implementation-specific configuration (previously only Cluster-level resources were allowed). 

Implementation restriction:
A union (with more than one term) cannot contain the
<a href="#Predeclared_identifiers">predeclared identifier</a> <code>comparable</code>
or interfaces that specify methods, or embed <code>comparable</code> or interfaces
that specify methods.
</p>

<p>
Interfaces that are not <a href="#Basic_interfaces">basic</a> may only be used as type
constraints, or as elements of other interfaces used as constraints.

- Added support for setting controller-manager log level online. ([#104571](https://github.com/kubernetes/kubernetes/pull/104571), [@h4ghhh](https://github.com/h4ghhh))

- Added fields `reason` and `fieldPath` into CRD validation rules to allow users to specify reason and field path when validation failed. ([#118041](https://github.com/kubernetes/kubernetes/pull/118041), [@cici37](https://github.com/cici37)) [SIG API Machinery]

- [`KT-58932`](https://youtrack.jetbrains.com/issue/KT-58932) Specify the priority between candidates with type and value receivers when doing callable reference inference
- [`KT-54254`](https://youtrack.jetbrains.com/issue/KT-54254) Specify that an annotation type cannot have itself as a nested element
- [`KT-53427`](https://youtrack.jetbrains.com/issue/KT-53427) Specify `@SubclassOptInRequired`

  
  When adding links which point to resources within git repositories, like
  KEPs or supporting documentation, please reference a specific commit and avoid
  linking directly to the master branch. This ensures that links reference a
  specific point in time, rather than a document that may change over time.
  

of v1.25, the PodSecurity `restricted` level no longer requires pods that set .spec.os.name="windows" to also set Linux-specific securityContext fields. If a 1.25+ cluster has unsupported [out-of-skew](https://kubernetes.io/releases/version-skew-policy/#kubelet) nodes prior to v1.23 and wants to ensure namespaces enforcing the `restricted` policy continue to require Linux-specific securityContext fields on all pods, ensure a version of the `restricted` prior to v1.25 is selected by labeling the namespace...

  
  When adding links which point to resources within git repositories, like
  KEPs or supporting documentation, please reference a specific commit and avoid
  linking directly to the master branch. This ensures that links reference a
  specific point in time, rather than a document that may change over time.