Add note about protected variables

doc/ci/cloud_deployment/index.md

@@ -58,6 +58,9 @@ Some credentials are required to be able to run `aws` commands:
    | `AWS_SECRET_ACCESS_KEY`        | Your Secret access key |
    | `AWS_DEFAULT_REGION`           | Your region code       |
 
+   NOTE:
+   When you create a variable it's set to be [protected by default](../variables/index.md#protect-a-cicd-variable). If you want to use the `aws` commands on branches or tags that are not protected, make sure to uncheck the **Protect variable** checkbox.
+
 1. You can now use `aws` commands in the `.gitlab-ci.yml` file of this project:
 
    ```yaml