// cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced
  // to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will
  // produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless
  // of whether the variable exists or not. Cannot be updated.

<p>
The syntax is specified using a
<a href="https://en.wikipedia.org/wiki/Wirth_syntax_notation">variant</a>
of Extended Backus-Naur Form (EBNF):
</p>

<pre class="grammar">
Syntax      = { Production } .
Production  = production_name "=" [ Expression ] "." .
Expression  = Term { "|" Term } .
Term        = Factor { Factor } .
Factor      = production_name | token [ "…" token ] | Group | Option | Repetition .

- kube-apiserver

  - the `--basic-auth-file` flag and authentication mode is deprecated and will be removed in a future release. It is not recommended for production environments. ([#81152](https://github.com/kubernetes/kubernetes/pull/81152), [@tedyu](https://github.com/tedyu))

com/presentation/d/1QUOsQxfEfHlMq4lPjlK2ewQHsr9peEKymDw5_XwZm8Q/edit?usp=sharing)). Bug fixes across bare metal tooling and production-ready user stories, such as the high availability use cases have been given priority for 1.15.

kubeadm, the cluster lifecycle building block, continues to receive features and stability work required for bootstrapping production clusters efficiently. kubeadm has promoted high availability (HA) capability to beta, allowing users to use the familiar `kubeadm...

  can also be scheduled to nodes with `GA` labels. ([#118923](https://github.com/kubernetes/kubernetes/pull/118923), [@AxeZhan](https://github.com/AxeZhan))
- Updated the generic apiserver library to produce an error if a new API server is configured with support for a data format other than JSON, YAML, or Protobuf. ([#121325](https://github.com/kubernetes/kubernetes/pull/121325), [@benluddy](https://github.com/benluddy)) [SIG API Machinery]

### Etcd v3.5.[0-2] data corruption

Data corruption issue was found in etcd v3.5.0 release that was shipped with 1.22 Kubernetes release. Please read up-to-date [production recommendations for etcd](https://github.com/etcd-io/etcd/tree/main/CHANGELOG).

## Urgent Upgrade Notes 

### (No, really, you MUST read this before you upgrade)

### Instrumentation

In v1.9 we focused on improving stability of the components owned by the SIG, including Heapster, Custom Metrics API adapters for Prometheus, and Stackdriver.

  purposes, you can use older kernels, as far back as 5.4, if you set the
  `nftables.skipKernelVersionCheck` option in the kube-proxy config, but this is not
  recommended in production since it may cause problems with other nftables
  users on the system.) ([#124152](https://github.com/kubernetes/kubernetes/pull/124152), [@danwinship](https://github.com/danwinship)) [SIG Network]

## Changelog since v1.10.5

### Action Required

## Changelog since v1.11.0

### Action Required