diff --git a/wsgi.md b/wsgi.md
index 160a3d4f..2b036755 100644
--- a/wsgi.md
+++ b/wsgi.md
@@ -7,5 +7,12 @@ permalink: /wsgi/
 Radicale is compatible with the WSGI specification. No special configuration
 is required.
 
+A configuration file can be set with the `RADICALE_CONFIG` environment variable,
+otherwise the default configuration is used.
+
+**Important:** The `None` authentication type disables all rights checking.
+Don't use it with `REMOTE_USER`. The development version of Radicale has
+the `remote_user` module for this use-case.
+
 Be reminded that Radicale's default configuration enforces limits on the
-maximum file size.
+maximum upload file size.