<p>
The following terms are used to denote specific Unicode character categories:
</p>
<pre class="ebnf">
newline        = /* the Unicode code point U+000A */ .
unicode_char   = /* an arbitrary Unicode code point except newline */ .
unicode_letter = /* a Unicode code point categorized as "Letter" */ .
unicode_digit  = /* a Unicode code point categorized as "Number, decimal digit" */ .
</pre>

<p>

## Kubefed

* Deprecate the `--secret-name` flag from `kubefed join`, instead generating the secret name arbitrarily. ([#42513](https://github.com/kubernetes/kubernetes/pull/42513), [@perotinus](https://github.com/perotinus))


### **Kubernetes API**
#### User Provided Extensions

- Kubelet can now parse PEM file containing both TLS certificate and key in arbitrary order. Previously key was always required to be first. ([#69536](https://github.com/kubernetes/kubernetes/pull/69536), [@awly](https://github.com/awly))

- Kube-apiserver: Resolved an issue causing unnecessary warning log messages about...

affinity/anti-affinity allow you to specify rules for restricting which node(s) a pod can schedule onto, based on the labels on the node. Pod affinity/anti-affinity allow you to specify rules for spreading and packing pods relative to one another, across arbitrary topologies (node, zone, etc.) These affinity rules are now be specified in a new-in-1.6 `affinity` field of the PodSpec. Kubernetes 1.6 continues to support the alpha `scheduler.alpha.kubernetes.io/affinity` annotation on the Pod if you explicitly...

- Kubelet: Closed a loophole that allowed static Pods to reference arbitrary ResourceClaims. Even though these Pods failed to run due to a sanity check, such references are now explicitly disallowed. ([#131844](https://github.com/kubernetes/kubernetes/pull/131844), [@pohly](https://github.com/pohly)) [SIG Apps, Auth and Node]...

- Kubelet: close a loophole where static pods could reference arbitrary ResourceClaims. The pods created by the kubelet then don't run due to a sanity check, but such references shouldn't be allowed regardless. ([#131875](https://github.com/kubernetes/kubernetes/pull/131875), [@pohly](https://github.com/pohly)) [SIG...

* the test/e2e/e2e.test binary can test arbitrary storage drivers, see the `-storage.testdriver` parameter ([#72836](https://github.com/kubernetes/kubernetes/pull/72836), [@pohly](https://github.com/pohly))

- Added GenericPVCDataSource feature gate to enable using arbitrary custom resources as the data source for a PVC. ([#88636](https://github.com/kubernetes/kubernetes/pull/88636), [@bswartz](https://github.com/bswartz)) [SIG Apps and Storage]

* Use CollisionCount for collision avoidance when creating ControllerRevisions in StatefulSet controller ([#50490](https://github.com/kubernetes/kubernetes/pull/50490), [@liyinan926](https://github.com/liyinan926))
* AWS: Arbitrarily choose first (lexicographically) subnet in AZ ([#50255](https://github.com/kubernetes/kubernetes/pull/50255), [@mattlandis](https://github.com/mattlandis))