Update remote_state.html.md

website/source/docs/providers/terraform/d/remote_state.html.md

@@ -43,3 +43,21 @@ The following attributes are exported:
 
 In addition, each output in the remote state appears as a top level attribute
 on the `terraform_remote_state` resource.
+
+## Root Outputs Only
+
+Only the root level outputs from the remote state are accessible. Outputs from modules within the state cannot be accessed. If you want a module output to be accessible via a remote state, you must thread the output through to a root output.
+
+An example is shown below:
+
+```
+module "app" {
+  source = "..."
+}
+
+output "app_value" {
+  value = "${module.app.value}"
+}
+```
+
+In this example, the output `value` from the "app" module is available as "app_value". If this root level output hadn't been created, then a remote state resource wouldn't be able to access the `value` output on the module.