diff --git a/docs/usage.rst b/docs/usage.rst
index 10bc14097b7489e920e6a047b30d61d87b729fd7..aa523a8e5af51b5f98afb5f3f01362c23abe6021 100644
--- a/docs/usage.rst
+++ b/docs/usage.rst
@@ -1236,6 +1236,9 @@ Before we start, here is a couple of useful pointers regarding the
 * Mails deliverd to local admin/application users are forwarded to ``root``
   account instead (this can be configured via ``website_mail_recipients`` role
   parameter.
+* If you ever find yourself mixing-up test and production websites, have a look
+  at ``environment_indicator`` role parameter. It lets you insert small strip at
+  bottom of each HTML page automatically.
 * Static content (non-PHP) is served directly by *Nginx*.
 * Each web application gets distinct sub-directory under ``/var/www``, named
   after the FQDN. All sub-directories created under there are created with
@@ -1485,6 +1488,9 @@ on the safe side:
 * Mails deliverd to local admin/application users are forwarded to ``root``
   account instead (this can be configured via ``website_mail_recipients`` role
   parameter.
+* If you ever find yourself mixing-up test and production websites, have a look
+  at ``environment_indicator`` role parameter. It lets you insert small strip at
+  bottom of each HTML page automatically.
 * Static content is served directly by *Nginx*.
 * Each web application gets distinct sub-directory under ``/var/www``, named
   after the FQDN. All sub-directories created under there are created with