within matching brace brackets.
</p>

<pre class="ebnf">
Block         = "{" StatementList "}" .
StatementList = { Statement ";" } .
</pre>

<p>
In addition to explicit blocks in the source code, there are implicit blocks:
</p>

<ol>
	<li>The <i>universe block</i> encompasses all Go source text.</li>

- Revert addition of Add `PersistentVolumeClaimDeletePoilcy` to `StatefulSet`API. ([#103747](https://github.com/kubernetes/kubernetes/pull/103747), [@mattcary](https://github.com/mattcary))

- Kubeadm: when adding new control plane nodes with "kubeadm join", ensure that the etcd member addition is performed only if a given member URL does not already exist in the list of members. Similarly, on "kubeadm reset" only remove an etcd member if its ID exists. ([#127621](https://github.com/kubernetes/kubernetes/pull/127621), [@SataQiu](https:...

SIG Cloud Provider has been focused on stabilizing the common APIs and interfaces consumed by cloud providers today. This involved auditing the cloud provider APIs for anything that should be deprecated as well as adding changes where necessary. In addition, SIG Cloud Provider has begun exploratory work around having a “cloud provider” e2e test suite which can be used to test common cloud provider functionalities with resources such as nodes and load balancers.

We are also continuing our...

disallow updates to all fields other than `.status` (not just `.spec` and `.metadata` as before). Also, `required` and `description` can be used at the root of the CRD OpenAPI validation schema when the `/status` subresource is enabled.

In addition, users can now create multiple versions of CustomResourceDefinitions, but without any kind of automatic conversion, and CustomResourceDefinitions now allow specification of additional columns for `kubectl get` output via the `spec.additionalPrinterColumns`...

- Kube-apiserver: multiple comma-separated protocols in a single X-Stream-Protocol-Version header are now recognized, in addition to multiple headers, complying with RFC2616 ([#89857](https://github.com/kubernetes/kubernetes/pull/89857), [@tedyu](https://github.com/tedyu)) [SIG API Machinery]

The SIG also provided match criteria that allow policy rules to match a source or destination CIDR. Both features are in beta. SIG Network also improved the kube-proxy to include an alpha IPVS mode in addition to the current iptables and userspace modes.

[SIG Network]: https://github.com/kubernetes/community/tree/master/sig-network

### SIG Scalability

  a) transformation error e.g. decryption failure, or b) the object failed to decode. Normal deletion flow is
  attempted first, and if it fails with a corrupt resource error then it triggers unsafe delete.
  In addition, when this feature is enabled, the 'details' field of 'Status' from the LIST response
  includes information that identifies the corrupt object(s).

## Changelog since v1.6.8

### Other notable changes

* StatefulSet: Set hostname/subdomain fields on new Pods in addition to the deprecated annotations, to allow mitigation of Pod DNS issues upon upgrading to Kubernetes v1.7.x. ([#50942](https://github.com/kubernetes/kubernetes/pull/50942), [@enisoc](https://github.com/enisoc))

SIG Windows is also including several addition to this release:
 - Direct Server Return (DSR) mode support, allowing large numbers of services to scale up efficiently
 - Windows containers  now honor CPU limits