- [IPv4/IPv6 dual-stack](https://kubernetes.io/docs/concepts/services-networking/dual-stack) enables the allocation of both IPv4 and IPv6 addresses to Pods and Services.
- [API Server Network Proxy](https://github.com/kubernetes/enhancements/blob/master/keps/sig-api-machinery/1281-network-proxy/README.md) going alpha in 1.16.

- Alpha support for field selectors on custom resources has been added. With the `CustomResourceFieldSelectors` feature gate enabled, the CustomResourceDefinition API now allows specifying `selectableFields`. Listing a field there enables filtering custom resources for that CustomResourceDefinition in list or watch requests. ([#122717](https://github.com/kubernetes/kubernetes/pull/122717), [@jpbetz](https://github.com/jpbetz))

An import declaration states that the source file containing the declaration
depends on functionality of the <i>imported</i> package
(<a href="#Program_initialization_and_execution">§Program initialization and execution</a>)
and enables access to <a href="#Exported_identifiers">exported</a> identifiers
of that package.
The import names an identifier (PackageName) to be used for access and an ImportPath
that specifies the package to be imported.
</p>

- 'Container `preStop` and `postStart` lifecycle handlers using `httpGet` now
  honor the specified `scheme` and `headers` fields. This enables setting custom
  headers and changing the scheme to `HTTPS`, consistent with container
  startup/readiness/liveness probe capabilities. Lifecycle handlers configured