add more documentation
diff --git a/buildkite/README.md b/buildkite/README.md
index 9c67b37..4ef76e1 100644
--- a/buildkite/README.md
+++ b/buildkite/README.md
@@ -37,14 +37,45 @@
## Pull Requests
+Bazel accepts contributions via pull requests. Contributions by members of the [bazelbuild]
+organisation as well as members of individual repositories (i.e. rule maintainers) are automatically
+whitelisted and will be build and tested on [Buildkite] automatically.
+An external contribution first needs to be verified by a member before it's build and tested on
+Bazel's CI. For external contributions you'll see a status as the below:
+
+![status verify pull request]
+
+A member can approve the pull request by clicking on *Details*, followed by *Verify Pull Request*
+
+![buildkite verify pull request]
+![buildkite pull request verified]
+
+Please vet those contributions carefully as they can run arbitrary code on our CI
+machines.
+
+
+When you open a new pull request, [Buildkite] will
+first try to verify the contribution based on the pull request creator. That is, contributions
+by users who are part of the bazelbuild organisation are automatically accepted
+
+ That is, if the creator of the pull request is a Bazel
+team member then it will create a new pull request there.
+
+When a new pull request is opened [Buildkite]
+will be triggered and first try to verify that the contribution
[Buildkite]: https://buildkite.com
[buildkite folder]: https://github.com/bazelbuild/continuous-integration/tree/master/buildkite
[rules_go]: https://github.com/bazelbuild/rules_go
+[Bazel]: https://github.com/bazelbuild/bazel
+[bazelbuild]: https://github.com/bazelbuild/
[pipelines]: https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/docs/assets/pipelines.png
[failed build step]: https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/docs/assets/failed-build-step.png
[flaky test]: https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/docs/assets/flaky-test.png
-[flaky test log]: https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/docs/assets/flaky-test-log.png
\ No newline at end of file
+[flaky test log]: https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/docs/assets/flaky-test-log.png
+[status verify pull request]: https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/docs/assets/status-verify-pull-request.png
+[buildkite verify pull request]: https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/docs/assets/buildkite-verify-pull-request.png
+[buildkite pull request verified]: https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/docs/assets/buildkite-pull-request-verified.png
\ No newline at end of file
diff --git a/buildkite/docs/assets/buildkite-pull-request-verified.png b/buildkite/docs/assets/buildkite-pull-request-verified.png
new file mode 100644
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diff --git a/buildkite/docs/assets/status-verify-pull-request.png b/buildkite/docs/assets/status-verify-pull-request.png
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