On this page https://kubectl.docs.kubernetes.io/references/kustomize/kustomization/crds/ it says:
The annotations can be put into openAPI definitions are:
- “x-kubernetes-annotation”: ""
- “x-kubernetes-label-selector”: ""
- “x-kubernetes-identity”: ""
- “x-kubernetes-object-ref-api-version”: “v1”,
- “x-kubernetes-object-ref-kind”: “Secret”,
- “x-kubernetes-object-ref-name-key”: “name”,
but it doesn't explain what those annotations are actually used for.