diff --git a/README.md b/README.md
index ce7cdd4..724dd5f 100644
--- a/README.md
+++ b/README.md
@@ -42,6 +42,16 @@ Kanboard and SSOwat
 Kanboard use SSOwat for user authentification (it means it use the user that the web server (nginx) sent him throught SSOwat), but can't list all user of the system.
 If you wish to add a user, just log in with that user into Kanboard so the software knows him and displays it.
 
+How to connect as external (non-SSOwat) users
+-------------------
+You have to edit this file `/var/www/kanboard/config.php`, find the line `define('REVERSE_PROXY_AUTH', true);` and change it from `true` to `false`.
+**Warning** this disables the possibility to connect with SSOwat users. You will *only* be able to connect with Kanboard users created inside of Kanboard.
+Then you can connect.
+
+**NB**: if you don't make that change, you will get the following error message "Access Forbidden".
+
+This is due to a Kanboard limitation.
+
 Developer infos
 ----------------