Reword

Author: javiereguiluz

routing.rst

@@ -815,8 +815,9 @@ parameter:
 .. tip::
 
     To give a ``null`` default value to any parameter, add nothing after the
-    ``?`` character (e.g. ``/blog/{page?}``). Also, remember to add the
-    ``?`` character before the function parameter type to make it permit null values (e.g. ``?int``) 
+    ``?`` character (e.g. ``/blog/{page?}``). If you do this, don't forget to
+    update the types of the related controller arguments to allow passing
+    ``null`` values (e.g. replace ``int $page`` by ``?int $page``).
 
 Parameter Conversion
 ~~~~~~~~~~~~~~~~~~~~