- Fixed bugs in handling of server-side apply, create, and update API requests for objects containing duplicate items in keyed lists.

- SSA treats certain structs as atomic ([#100684](https://github.com/kubernetes/kubernetes/pull/100684), [@Jefftree](https://github.com/Jefftree)) [SIG API Machinery, Auth, Node and Storage]

#### Create subcommands
  - `create poddisruptionbudget` ([#36646](https://github.com/kubernetes/kubernetes/pull/36646), [@kargakis](https://github.com/kargakis))
  - `create clusterrole` ([#41538](https://github.com/kubernetes/kubernetes/pull/41538), [@xingzhou](https://github.com/xingzhou))

  // The RuntimeClass admission controller will reject Pod create requests which have the overhead already
  // set. If RuntimeClass is configured and selected in the PodSpec, Overhead will be set to the value
  // defined in the corresponding RuntimeClass, otherwise it will remain unset and treated as zero.

### SIG Scalability

SIG Scalability has mostly focused on stability and deflaking our tests, investing into framework for writing scalability tests (ClusterLoader v2) with a goal to migrate all tests to it by the end of 2018 and on the work towards extending definition of Kubernetes scalability by providing more/better user-friendly SLIs/SLOs.

### SIG Scheduling

  - A namespaced object with an ownerReference referencing a uid of a namespaced kind which does not exist in the same namespace is now consistently treated as though that owner does not exist, and the child object is deleted.

</pre>

<p>
In <a href="https://www.unicode.org/versions/Unicode8.0.0/">The Unicode Standard 8.0</a>,
Section 4.5 "General Category" defines a set of character categories.
Go treats all characters in any of the Letter categories Lu, Ll, Lt, Lm, or Lo
as Unicode letters, and those in the Number category Nd as Unicode digits.
</p>

<h3 id="Letters_and_digits">Letters and digits</h3>

<p>

* Checks CREATE admission for create-on-update requests instead of UPDATE admission ([#65572](https://github.com/kubernetes/kubernetes/pull/65572), [@yue9944882](https://github.com/yue9944882))

* Fix panic create/update CRD when mutating/validating webhook configured. ([#61404](https://github.com/kubernetes/kubernetes/pull/61404), [@hzxuzhonghu](https://github.com/hzxuzhonghu))

  error as the real clients; in particular, a failed Get(), Create(), etc, no longer
  returns `nil`. (It now returns a pointer to a zero-valued object, like the real
  clients do.) This will break some downstream unit tests that were testing
  `result == nil` rather than `err != nil`, and in some cases may expose bugs