PrimaryExpr TypeAssertion |
                PrimaryExpr Arguments .

Selector      = "." identifier .
Index         = "[" Expression [ "," ] "]" .
Slice         = "[" [ Expression ] ":" [ Expression ] "]" |
                "[" [ Expression ] ":" Expression ":" Expression "]" .
TypeAssertion = "." "(" Type ")" .
Arguments     = "(" [ ( ExpressionList | Type [ "," ExpressionList ] ) [ "..." ] [ "," ] ] ")" .
</pre>

- Fixed the example validation rule in godoc:
  
  When configuring a JWT authenticator:
  
  If username.expression uses 'claims.email', then 'claims.email_verified' must be used in
  username.expression or extra[*].valueExpression or claimValidationRules[*].expression.
  An example claim validation rule expression that matches the validation automatically

- When configuring a JWT authenticator:
  

- The "value" part in the `wait --for=jsonpath='{expression}'[=value]` is now
  optional. If the value is not provided i.e., the command looks like `wait --for=jsonpath='{expression}'`
  then the wait condition is interpreted as matched when the expression returns

### Promoted CRD Validation Expression Language to Beta

- Added `messageExpression` to `ValidatingAdmissionPolicy`, to set custom failure message via CEL expression. ([#116397](https://github.com/kubernetes/kubernetes/pull/116397), [@jiahuif](https://github.com/jiahuif)) [SIG API Machinery]
- Added a new IPAddress object kind

- Validation rules for Custom Resource Definitions can be written in the [CEL expression language](https://github.com/google/cel-spec) using the `x-kubernetes-validations` extension in OpenAPIv3 schemas (alpha). This is gated by the alpha "CustomResourceValidationExpressions" feature gate. ([#106051](https://github.com/kubernetes/k...

- Added name validation for dynamic client methods in client-go ([#75072](https://github.com/kubernetes/kubernetes/pull/75072), [@lblackstone](https://github.com/lblackstone))
- CustomResourceDefinition with invalid regular expression in the pattern field of OpenAPI v3 validation schemas are no longer considered structural. ([#78453](https://github.com/kubernetes/kubernetes/pull/78453), [@sttts](https://github.com/sttts))

- When updating a CRD, per-expression cost limit check are now skipped for `x-kubernetes-validations` rules of versions that are not mutated. ([#121460](https://github.com/kubernetes/kubernetes/pull/121460), [@jiahuif](https://github.com/jiahuif))

- Added enforcement of an upper cost bound for DRA evaluations of CEL. The API server and scheduler now enforce an upper bound on the cost and runtime steps required for evaluating a CEL expression. ([#128101](https://github.com/kubernetes/kubernetes/pull/128101), [@pohly](https://github.com/pohly)) [SIG API Machinery and Node]