diff --git a/source/configuration/bffh_config.md b/source/configuration/bffh_config.md
index 4d89111..8731c8d 100644
--- a/source/configuration/bffh_config.md
+++ b/source/configuration/bffh_config.md
@@ -18,7 +18,15 @@ listens =
 ```
 
 ### `mqtt_url`
-Contains the Address for the MQTT Server BFFH connects to
+Contains the Address for the MQTT Server BFFH connects to.
+
+The Address has the format `<protocol>://[user]:[password]@<server>:[port]`
+
+* `protocol` is required and can be one of: `mqtt`,`tcp`,`mqtts`,`ssl`
+* `user` and `password` are optional
+* `server` is required and can be an ip address or a hostname
+* `port` is optional
+
 **Example:**
 ```
 mqtt_url = "tcp://localhost:1883"