diff --git a/file b/file
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@@ -1 +1,12 @@
-Test-W
\ No newline at end of file
+Test-W
+sandbox
+=======
+
+This is a sandbox so that lovely developers can test the tools
+and processes used for OpenStack development.
+For detail, see the chapter "`Learn the Gerrit Workflow in the
+Sandbox <https://docs.openstack.org/infra/manual/sandbox.html>`_"
+in Infrastructure User Manual.
+
+Developer's Guide:
+https://docs.openstack.org/infra/manual/developers.html