- CEL cost estimator no longer treats enums as unbounded strings when determining its length. Instead, the length is set to the longest possible enum value. ([#121085](https://github.com/kubernetes/kubernetes/pull/121085), [@jiahuif](https://github.com/jiahuif)) [SIG API Machinery]

- Omit enum declarations from the static openapi file captured at https://git.k8s.io/kubernetes/api/openapi-spec. This file is used to generate API clients, and use of enums in those generated clients (rather than strings) can break forward compatibility with additional future values in those fields. See https://issue.k8s.io/109177 for details....

- Fixed `kubectl explain` to show enum for field types if they were defined. ([#123023](https://github.com/kubernetes/kubernetes/pull/123023), [@ah8ad3](https://github.com/ah8ad3))

## Changelog since v1.23.5

## Changes by Kind

### API Change

- Omits alpha-level enums from the static openapi file captured in api/openapi-spec ([#109179](https://github.com/kubernetes/kubernetes/pull/109179), [@liggitt](https://github.com/liggitt)) [SIG Apps and Auth]

### Feature

- Removed `resizeStatus` enum from `pvc.Status` and replaced with `AllocatedResourceStatus`. ([#116335](https://github.com/kubernetes/kubernetes/pull/116335), [@gnufied](https://github.com/gnufied)) [SIG API Machinery, Apps, Auth, Node, Storage and Testing]

## Changelog since v1.21.5

## Changes by Kind

### API Change

- Kube-apiserver: Fixes handling of CRD schemas containing literal null values in enums (#104989, @liggitt) [SIG API Machinery, Apps and Network]

### Feature

- Kubernetes is now built with Golang 1.16.9 (#105672, @cpanato) [SIG Cloud Provider, Instrumentation, Release and Testing]

## Changelog since v1.22.2

## Changes by Kind

### API Change

- Kube-apiserver: Fixes handling of CRD schemas containing literal null values in enums (#104988, @liggitt) [SIG API Machinery, Apps and Network]

### Feature

- Kubernetes is now built with Golang 1.16.9 (#105671, @cpanato) [SIG Cloud Provider, Instrumentation, Release and Testing]

## Changelog since v1.20.11

## Changes by Kind

### API Change

- Kube-apiserver: Fixes handling of CRD schemas containing literal null values in enums (#104990, @liggitt) [SIG API Machinery, Apps and Network]

### Bug or Regression

- Detach volumes from vSphere nodes not tracked by attach-detach controller (#104910, @gnufied) [SIG Cloud Provider and Storage]