- The list-type of the alpha `resourceClaims` field introduced to `Pods` in `1.26.0` was modified from `set` to `map`, resolving an incompatibility with use of this schema in `CustomResourceDefinitions` and with server-side apply. ([#114585](https://github.com/kubernetes/kubernetes/pull/114585), [@JoelSpeed](https://github.com/JoelSpeed))

- Added new `CRDValidationRatcheting` alpha feature. During a PATCH or UPDATE Validation Ratcheting discards errors thrown by unchanged portions of the resource from most OpenAPI schema validations. ([#118990](https://github.com/kubernetes/kubernetes/pull/118990), [@alexzielenski](https://github.com/alexzielenski))

- Fixed bug where providing a FieldPath to a CRD Validation Rule would erroneously affect the reported field path of other unrelated CRD Validation Rules on the same schema. ([#123475](https://github.com/kubernetes/kubernetes/pull/123475), [@alexzielenski](https://github.com/alexzielenski))

- Added `optionalOldSelf` to `x-kubernetes-validations` to support ratcheting CRD schema constraints. ([#121034](https://github.com/kubernetes/kubernetes/pull/121034), [@alexzielenski](https://github.com/alexzielenski))