- Added warnings to the Services API. Kubernetes now warns for Services in the case of:
  - IPv4 addresses with leading zeros
  - IPv6 address in non-canonical format (RFC 5952) ([#114505](https://github.com/kubernetes/kubernetes/pull/114505), [@aojea](https://github.com/aojea))

- Removed leading zeros from the etcd member ID in kubeadm log messages. ([#117919](https://github.com/kubernetes/kubernetes/pull/117919), [@dlipovetsky](https://github.com/dlipovetsky)) [SIG Cluster Lifecycle]

- In the PriorityLevelConfiguration object, the `nominalConcurrencyShares` field now accepts a zero value in both the `flowcontrol.apiserver.k8s.io/v1` and `flowcontrol.apiserver.k8s.io/v1beta3` APIs.
   ([#123001](https://github.com/kubernetes/kubernetes/pull/123001), [@tkashem](https://github.com/tkashem))

- Fixed CEL estimated cost of `replace()` to handle a zero length replacement string correctly.
  Previously this would cause the estimated cost to be higher than it should be. ([#120097](https://github.com/kubernetes/kubernetes/pull/120097), [@jpbetz](https://github.com/jpbetz)) [SIG API Machinery]