- If a bad flag is supplied to a kubectl command, only a tip to run `--help` is printed, instead of the usage menu.  Usage menu is printed upon running `kubectl command --help`. ([#82423](https://github.com/kubernetes/kubernetes/pull/82423), [@sallyom](https://github.com/sallyom))

- Kubeadm: deprecate self-hosting support. The experimental command "kubeadm alpha self-hosting" is now deprecated and will be removed in a future release. ([#95125](https://github.com/kubernetes/kubernetes/pull/95125), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

- Kubeadm: remove the deprecated command `kubeadm config view`. A replacement for this command is `kubectl get cm -n kube-system kubeadm-config -o=jsonpath="{.data.ClusterConfiguration}"` ([#102071](https://github.com/kubernetes/kubernetes/pull/102071), [@neolit123](https://github.com/neolit123))

- Kubeadm: allow the `certs check-expiration` command to not require the existence of the cluster CA key (ca.key file) when checking the expiration of managed certificates in kubeconfig files. ([#106854](https://github.com/kubernetes/kubernetes/pull/106854), [@neolit123](https://github.com/neolit123))

- Fix a regression where kubeadm bails out with a fatal error when an optional version command line argument is supplied to the "kubeadm upgrade plan" command ([#94421](https://github.com/kubernetes/kubernetes/pull/94421), [@rosti](https://github.com/rosti)) [SIG Cluster Lifecycle]

- `pod.Spec.RuntimeClassName` field is now available in kubectl describe command. ([#110914](https://github.com/kubernetes/kubernetes/pull/110914), [@yeahdongcn](https://github.com/yeahdongcn))

### Other (Cleanup or Flake)

### kubectl rolling-update: < v1.4.0 client vs >=v1.4.0 cluster

Old version kubectl's rolling-update command is compatible with Kubernetes 1.4 and higher only if you specify a new replication controller name. You will need to update to kubectl 1.4 or higher to use the rolling update command against a 1.4 cluster if you want to keep the original name, or you'll have to do two rolling updates.

* Drain pods created from ReplicaSets in 'kubectl drain' ([#23689](https://github.com/kubernetes/kubernetes/pull/23689), [@maclof](https://github.com/maclof))
* GCI: Update the command to get the image ([#24987](https://github.com/kubernetes/kubernetes/pull/24987), [@andyzheng0831](https://github.com/andyzheng0831))

## Major Themes

- StatefulSets (ex-PetSets)
  - StatefulSets are beta now (fixes and stabilization)
- Improved Federation Support
  - New command: `kubefed`
  - DaemonSets
  - Deployments
  - ConfigMaps
- Simplified Cluster Deployment
  - Improvements to `kubeadm`
  - HA Setup for Master
- Node Robustness and Extensibility

* kubeadm: a new command `kubeadm upgrade node` is introduced for upgrading nodes (both secondary control-plane nodes and worker nodes)  ([#78408](https://github.com/kubernetes/kubernetes/pull/78408), [@fabriziopandini](https://github.com/fabriziopandini))
    * The command `kubeadm upgrade node config` is now deprecated; use `kubeadm upgrade node` instead.