- The `/swaggerapi/*` schema docs, deprecated since 1.7, have been removed in favor of the /openapi/v2 schema docs. ([#72924](https://github.com/kubernetes/kubernetes/pull/72924), [@liggitt](https://github.com/liggitt))

        * In responses, the `set` will be converted to a `list`.
        * The generated schema will specify that the `set` values are unique (using JSON Schema's `uniqueItems`).
* `bytes`:
    * Standard Python `bytes`.
    * In requests and responses will be treated as `str`.
    * The generated schema will specify that it's a `str` with `binary` "format".
* `Decimal`:
    * Standard Python `Decimal`.

* Add port forwarding for rkt with kvm stage1 ([#32126](https://github.com/kubernetes/kubernetes/pull/32126), [@jjlakis](https://github.com/jjlakis))

  // acceptedTypes describes the kinds that this endpoint accepts.
  // Subresources may accept the standard content types or define
  // custom negotiation schemes. The list may not be exhaustive for
  // all operations.
  // +listType=map
  // +listMapKey=group
  // +listMapKey=version
  // +listMapKey=kind
  repeated k8s.io.apimachinery.pkg.apis.meta.v1.GroupVersionKind acceptedTypes = 3;

## 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

- Fixed nil pointer error in `NodeVolumeLimits` csi logging ([#115179](https://github.com/kubernetes/kubernetes/pull/115179), [@sunnylovestiramisu](https://github.com/sunnylovestiramisu))
- Fixed panic validating custom resource definition schemas that set `multipleOf` to 0 ([#114869](https://github.com/kubernetes/kubernetes/pull/114869), [@liggitt](https://github.com/liggitt))

			cacheStore.Store(embeddedCacheKey, true)
			if field.EmbeddedSchema, err = getOrParse(fieldValue.Interface(), cacheStore, embeddedNamer{Table: schema.Table, Namer: schema.namer}); err != nil {
				schema.err = err
			}

			for _, ef := range field.EmbeddedSchema.Fields {
				ef.Schema = schema
				ef.OwnerSchema = field.EmbeddedSchema
				ef.BindNames = append([]string{fieldStruct.Name}, ef.BindNames...)

//     and the version of the actual struct is irrelevant.
//  5. We cannot easily change it.  Because this type is embedded in many locations, updates to this type
//     will affect numerous schemas.  Don't make new APIs embed an underspecified API type they do not control.
//
// Instead of using this type, create a locally provided and used type that is well-focused on your reference.

- Added support for CEL(Common Expression Language) expressions and `additionalProperties` to be used under nested quantifiers in CRD schemas. ([#124381](https://github.com/kubernetes/kubernetes/pull/124381), [@alexzielenski](https://github.com/alexzielenski)) [SIG API Machinery]
- Added support for building Windows kube-proxy container image.

* Eviction thresholds set to 0% or 100% will turn off eviction. ([#59681](https://github.com/kubernetes/kubernetes/pull/59681), [@mtaufen](https://github.com/mtaufen))

* CustomResourceDefinitions: OpenAPI v3 validation schemas containing `$ref`references are no longer permitted. Before upgrading, ensure CRD definitions do not include those `$ref` fields. ([#58438](https://github.com/kubernetes/kubernetes/pull/58438), [@carlory](https://github.com/carlory))