Improvements

Author: javiereguiluz

security/voters.rst

@@ -324,8 +324,12 @@ security configuration:
             ],
         ]);
 
+Custom Access Decision Strategy
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
 If none of the built-in strategies fits your use case, define the ``service``
-option to use a custom service as the Access Decision Manager:
+option to use a custom service as the Access Decision Manager (your service
+must implement the :class:`Symfony\\Component\\Security\\Core\\Authorization\\AccessDecisionManagerInterface`):
 
 .. configuration-block::