or move it to a safe location. `kubadm certs renew` will renew the certificate in `super-admin.conf` to one year if the file exists; if it does not exist a "MISSING" note will be printed. `kubeadm upgrade apply` for this release will migrate this particular node to the two file setup. Subsequent kubeadm releases will continue to optionally renew the certificate in `super-admin.conf` if the file exists on disk and if renew on upgrade is not disabled. `kubeadm join --control-plane` will now generate...

//  2. Invalid usage help.  It is impossible to add specific help for individual usage.  In most embedded usages, there are particular
//     restrictions like, "must refer only to types A and B" or "UID not honored" or "name must be restricted".
//     Those cannot be well described when embedded.

### RBAC
* Default ClusterRole and ClusterRoleBinding objects are automatically updated at server start to add missing permissions and subjects (extra permissions and subjects are left in place). To prevent autoupdating a particular role or rolebinding, annotate it with `rbac.authorization.kubernetes.io/autoupdate=false`. ([#41155](https://github.com/kubernetes/kubernetes/pull/41155), [@liggitt](https://github.com/liggitt))

- Transparent kube-proxy restarts when using IPVS are now allowed. ([#75283](https://github.com/kubernetes/kubernetes/pull/75283), [@lbernail](https://github.com/lbernail))
- Packets considered INVALID by conntrack are now dropped. In particular, this fixes
a problem where spurious retransmits in a long-running TCP connection to a service
IP could result in the connection being closed with the error "Connection reset by

* IPVS: Disable graceful termination for UDP traffic to solve issues with high number of UDP connections (DNS / syslog in particular) ([#77802](https://github.com/kubernetes/kubernetes/pull/77802), [@lbernail](https://github.com/lbernail))

- CustomResourceDefinitions introduce `x-kubernetes-map-type` annotation as a CRD API extension. Enables this particular validation for server-side apply. ([#84113](https://github.com/kubernetes/kubernetes/pull/84113), [@enxebre](https://github.com/enxebre))

## Other notable changes
### API Machinery

0 and 255 inclusive.  Hexadecimal escapes satisfy this condition
by construction. The escapes <code>\u</code> and <code>\U</code>
represent Unicode code points so within them some values are illegal,
in particular those above <code>0x10FFFF</code> and surrogate halves.
</p>

<p>
After a backslash, certain single-character escapes represent special values:
</p>

<pre class="grammar">
\a   U+0007 alert or bell

SIG Storage made a lot of progress in the 1.18 release.
In particular, the following storage features are moving to GA in Kubernetes 1.18:
- Raw Block Support: Allow volumes to be surfaced as block devices inside containers instead of just mounted filesystems.

    *   Clients using older endpoints will be unaffected. This change is only at the REST API level and is independent of the default behavior of particular clients (e.g. this does not affect the default for the kubectl `--cascade` flag).
    *   If you upgrade your client-go libs and use the `AppsV1()` interface, please note that the default garbage collection behavior is changed.

- Fixed a regression introduced in 1.22.4 where Azure load balancers were not kept up to date with the state of cluster nodes. In particular, nodes that are not in the ready state and are not newly created (i.e. not having the `node.cloudprovider.kubernetes.io/uninitialized` taint) now get removed from Azure load balancers. ([#109933](https://github.com/kubernetes/kubernetes/pull/109933),...