diff --git a/README.rst b/README.rst
index 67199fe..165d75d 100644
--- a/README.rst
+++ b/README.rst
@@ -11,6 +11,15 @@ Requires
 ========
 - Tryton 6.0
 
+How to
+======
+
+The module extends the cash accounts in mds-cashbook with
+the ability to store quantities. You are free to choose the
+unit of measurement. It uses the current price data
+from the mds-investment module.
+You can monitor trading fees, dividends and sales profits.
+
 Changes
 =======