Within a parenthesized <code>const</code> declaration list the
expression list may be omitted from any but the first ConstSpec.
Such an empty list is equivalent to the textual substitution of the
first preceding non-empty expression list and its type if any.
Omitting the list of expressions is therefore equivalent to
repeating the previous list.  The number of identifiers must be equal
to the number of expressions in the previous list.

  // +optional
  optional string imagePullPolicy = 14;

  // SecurityContext defines the security options the container should be run with.
  // If set, the fields of SecurityContext override the equivalent fields of PodSecurityContext.
  // More info: https://kubernetes.io/docs/tasks/configure-pod-container/security-context/
  // +optional
  optional SecurityContext securityContext = 15;

- Deprecate the instance type beta label (`beta.kubernetes.io/instance-type`) in favor of its GA equivalent: `node.kubernetes.io/instance-type` ([#82049](https://github.com/kubernetes/kubernetes/pull/82049), [@andrewsykim](https://github.com/andrewsykim))

- When using `kubectl replace` (or the equivalent API call) on a Service, the caller no longer needs to do a read-modify-write cycle to fetch the allocated values for `.spec.clusterIP` and `.spec.ports[].nodePort`.  Instead the API server will automatically carry these forward from the original...

    * Before upgrading, users must ensure their controller manager will enable the csrapproving controller, create an RBAC ClusterRole and ClusterRoleBinding to approve CSRs for the same group, then upgrade. Example roles to enable the equivalent behavior can be found in the [TLS bootstrapping](https://kubernetes.io/docs/admin/kubelet-tls-bootstrapping/) documentation.


### kubectl (CLI)

- Third party device monitoring is now beta, and enabled...

  127.0.0.1. (Also note that there are currently no command-line arguments
  for the nftables-specific config; you will need to use a config file if
  you want to set the equivalent of any of the `--iptables-xxx` options.)
  
  As this code is still very new, it has not been heavily optimized yet;
  while it is expected to _eventually_ have better performance than the

### Other notable changes

### Node

- The `WaitFor` and `WaitForWithContext` functions in the wait package have now been marked private. Callers should use the equivalent `Poll*` method with a zero duration interval. ([#115116](https://github.com/kubernetes/kubernetes/pull/115116), [@smarterclayton](https://github.com/smarterclayton))