diff --git a/doc/source/deploy_install_guides/r3_release/distributed_cloud/index.rst b/doc/source/deploy_install_guides/r3_release/distributed_cloud/index.rst
index c8a0a9953..f6a879b9f 100644
--- a/doc/source/deploy_install_guides/r3_release/distributed_cloud/index.rst
+++ b/doc/source/deploy_install_guides/r3_release/distributed_cloud/index.rst
@@ -106,6 +106,12 @@ subcloud Management and OAM IP subnet and the SystemController Management and
 OAM IP subnet, respectively. For more information, see the
 `Install a Subcloud`_ section later in this guide.
 
+.. note::
+
+    All messaging between SystemControllers and Subclouds uses the ``admin``
+    REST API service endpoints which, in this distributed cloud environment,
+    are all configured for secure HTTPS. Certificates for these HTTPS
+    connections are managed internally by StarlingX.
 
 ---------------------------------------
 Install and provision the central cloud
diff --git a/doc/source/deploy_install_guides/r4_release/distributed_cloud/index.rst b/doc/source/deploy_install_guides/r4_release/distributed_cloud/index.rst
index edb1d2f76..cb4c63727 100644
--- a/doc/source/deploy_install_guides/r4_release/distributed_cloud/index.rst
+++ b/doc/source/deploy_install_guides/r4_release/distributed_cloud/index.rst
@@ -106,6 +106,12 @@ subcloud Management and OAM IP subnet and the SystemController Management and
 OAM IP subnet, respectively. For more information, see the
 `Install a Subcloud`_ section later in this guide.
 
+.. note::
+
+    All messaging between SystemControllers and Subclouds uses the ``admin``
+    REST API service endpoints which, in this distributed cloud environment,
+    are all configured for secure HTTPS. Certificates for these HTTPS
+    connections are managed internally by StarlingX.
 
 ---------------------------------------
 Install and provision the central cloud