diff --git a/README.md b/README.md
index 2c7de04..e33aaef 100644
--- a/README.md
+++ b/README.md
@@ -13,5 +13,20 @@ You have to define at least 3 things in your settings
 
 Those two are optional
 
-    mongo.username = username for authentication to the db
-    mongo.password = password used for authentication to the db
+    mongo.username.dbname = username for authentication to dbname
+    mongo.password.dbname = password used for authentication to dbname
+
+Mongodb uri format
+==================
+
+The format of the mongodb uri is the one that use mongodb. You can pass
+multiple uris to mongo.uri. They must be separated by newlines and they 
+must be uniques. MongoDb will not accept two identical uri. But it will
+accept uris reffering to the same host and same server if hostnames are 
+not identical.
+
+    mongo.uri = localhost
+                127.0.0.1
+
+Is something valid and will work. Connection will open 2 connections on the 
+default port.