* Provide kubernetes-controller-manager flags to control volume attach/detach reconciler sync.  The duration of the syncs can be controlled, and the syncs can be shut off as well.  ([#39551](https://github.com/kubernetes/kubernetes/pull/39551), [@chrislovecnm](https://github.com/chrislovecnm))

* **[alpha]** New Bootstrap Token authentication and management method. Works well with kubeadm. kubeadm now supports managing tokens, including time based expiration, after the cluster is launched.  See [kubeadm reference docs](https://kubernetes.io/docs/admin/kubeadm/#manage-tokens) for details.

- Kube-controller-manager's help will include controllers behind a feature gate in `--controllers` flag ([#120371](https://github.com/kubernetes/kubernetes/pull/120371), [@atiratree](https://github.com/atiratree)) [SIG API Machinery]

* Trusty: Avoid reaching GCE custom metadata size limit ([#22818](https://github.com/kubernetes/kubernetes/pull/22818), [@andyzheng0831](https://github.com/andyzheng0831))
* Update kubectl help for 1.2 resources ([#23305](https://github.com/kubernetes/kubernetes/pull/23305), [@janetkuo](https://github.com/janetkuo))

- Kubectl shell completions for the bash shell now include descriptions. ([#113636](https://github.com/kubernetes/kubernetes/pull/113636), [@marckhouzam](https://github.com/marckhouzam))

Updated Plugin Mechanism for kubectl is Graduating to Stable ([#579](https://github.com/kubernetes/enhancements/issues/579))

- Extends functionality to kubectl to support extensions adding new commands as well as overriding specific subcommands (at any depth).
- Documentation fixes

* Add support for 3rd party objects to kubectl label ([#24882](https://github.com/kubernetes/kubernetes/pull/24882), [@brendandburns](https://github.com/brendandburns))
* Move shell completion generation into 'kubectl completion' command ([#23801](https://github.com/kubernetes/kubernetes/pull/23801), [@sttts](https://github.com/sttts))

    * When using an in-cluster client with an empty configuration, the `--namespace` flag is now honored ([#46299](https://github.com/kubernetes/kubernetes/pull/46299), [@ncdc](https://github.com/ncdc))

    * The help message for missingResourceError is now generic ([#45582](https://github.com/kubernetes/kubernetes/pull/45582), [@CaoShuFeng](https://github.com/CaoShuFeng))