as deprecated and print a warning if it is used directly; it will be removed in
  a future release. Add a replacement sub-phase ''enable-client-cert-rotation''.' ([#124419](https://github.com/kubernetes/kubernetes/pull/124419), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

- Added warnings for overlap paths in ConfigMap, Secret, DownwardAPI, Projected. Added warning for cases when ProjectedVolume with sources is provided. ([#121968](https://github.com/kubernetes/kubernetes/pull/121968), [@Peac36](https://github.com/Peac36))

  - The `--experimental-encryption-provider-config` flag is deprecated in favor of `--encryption-provider-config`. The old flag is accepted with a warning but will be removed in 1.14. ([#71206](https://github.com/kubernetes/kubernetes/pull/71206),...

For new clusters if you have not configured the cgroup driver explicitly you might get a failure in the `kubelet` on driver mismatch (kubeadm clusters should be using the `systemd` driver). Also remove the `IsDockerSystemdCheck` preflight check (warning) that checks if the Docker cgroup driver is set to `systemd`. Ideally such detection / coordination should be on the side of CRI implementers and the kubelet (tracked [here](https://github.com/kubernetes/kubernetes/issues/99808)). Please see the ...

- e2e storage tests now run faster and are easier to read ([#72434](https://github.com/kubernetes/kubernetes/pull/72434), [@pohly](https://github.com/pohly))
- `e2e.test` now rejects unknown `--provider` values instead of merely warning about them. An empty provider name is not accepted anymore and was replaced by `skeleton` (a provider with no special behavior). ([#73402](https://github.com/kubernetes/kubernetes/pull/73402), [@pohly](https://github.com/pohly))

  When an Indexed Job has a number of completions higher than 10^5 and parallelism higher than 10^4, and a big number of Indexes fail, Kubernetes might not be able to track the termination of the Job. Kubernetes now emits a warning, at Job creation, when the Job manifest exceeds both of these limits. ([#118420](https://github.com/kubernetes/kubernetes/pull/118420), [@alculquicondor](https://github.com/alculquicondor)) [SIG Apps]

- Fixed a bug which kubectl would emit duplicate warning messages for flag names that contain an underscore and recommend using a nonexistent flag in some cases. ([#103852](https://github.com/kubernetes/kubernetes/pull/103852), [@brianpursley](https://github.com/brianpursley))

- Added a warning when alpha metrics are used with emulated versions. ([#132276](https://github.com/kubernetes/kubernetes/pull/132276), [@michaelasp](https://github.com/michaelasp)) [SIG API Machinery and Architecture]

- [v1.6.0](#v160)
  - [Downloads for v1.6.0](#downloads-for-v160)
    - [Client Binaries](#client-binaries-13)
    - [Server Binaries](#server-binaries-13)
  - [WARNING: etcd backup strongly recommended](#warning-etcd-backup-strongly-recommended)
  - [Major updates and release themes](#major-updates-and-release-themes)
  - [Action Required](#action-required-1)
    - [Certificates API](#certificates-api)

- Kubeadm: perform pre-flight validation on host/node name upon `kubeadm init` and `kubeadm join`, showing warnings on non-compliant names ([#99194](https://github.com/kubernetes/kubernetes/pull/99194), [@pacoxu](https://github.com/pacoxu))