- [CustomResourceDefinition OpenAPI Publishing](#customresourcedefinition-openapi-publishing)
  - [Cluster Lifecycle Stability and Usability Improvements](#cluster-lifecycle-stability-and-usability-improvements)
  - [Continued improvement of CSI](#continued-improvement-of-csi)
    - [Additional Notable Feature Updates](#additional-notable-feature-updates)
  - [Known Issues](#known-issues)

- To enhance usability and developer experience, CRD validation rules now support direct use of (CEL) reserved keywords as field names in object validation expressions.

### AWS

  users on the system.) ([#124152](https://github.com/kubernetes/kubernetes/pull/124152), [@danwinship](https://github.com/danwinship)) [SIG Network]

- The pod admission error message was improved for usability. ([#112644](https://github.com/kubernetes/kubernetes/pull/112644), [@vitorfhc](https://github.com/vitorfhc)) [SIG Node]
- The time duration of a failed or unschedulable scheduling attempt will be longer, it 

### Scalability

* Added the ability to limit the increase in apiserver memory usage when audit logging with buffering is enabled. ([#61118](https://github.com/kubernetes/kubernetes/pull/61118), [@shyamjvs](https://github.com/shyamjvs))

SIG Scalability has mostly focused on stability and deflaking our tests, investing into framework for writing scalability tests (ClusterLoader v2) with a goal to migrate all tests to it by the end of 2018 and on the work towards extending definition of Kubernetes scalability by providing more/better user-friendly SLIs/SLOs.

### SIG Scheduling

PodSecurityPolicy was initially [deprecated in v1.21](https://kubernetes.io/blog/2021/04/06/podsecuritypolicy-deprecation-past-present-and-future/), and with the release of v1.25, it has been removed. The updates required to improve its usability would have introduced breaking changes, so it became necessary to remove it in favor of a more friendly replacement. That replacement is [Pod Security Admission](https://kubernetes.io/docs/concepts/security/pod-security-admission/), which graduates...

tolerate the NoSchedule taint if the taint is added to a Node.  There is an open PR ([#48189](https://github.com/kubernetes/kubernetes/pull/48189)) to resolve this issue, but as this issue also exists in 1.6, and as we do not wish to risk release stability by merging it directly prior to a release without sufficient testing, we have decided to defer merging the PR until the next point release for each minor version ([#48190](https://github.com/kubernetes/kubernetes/pull/48190)).

* Protobuf...

- kube-proxy metrics are now marked as with the ALPHA stability level. ([#81626](https://github.com/kubernetes/kubernetes/pull/81626), [@logicalhan](https://github.com/logicalhan))