optional string kind = 1;

  // Namespace of the referent.
  // More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/
  // +optional
  optional string namespace = 2;

  // Name of the referent.
  // More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/names/#names
  // +optional
  optional string name = 3;

  // UID of the referent.

## Introduction to v1.8.0

Kubernetes version 1.8 includes new features and enhancements, as well as fixes to identified issues. The release notes contain a brief overview of the important changes introduced in this release. The content is organized by Special Interest Groups ([SIGs][]).

For initial installations, see the [Setup topics][] in the Kubernetes
documentation.