diff --git a/reference/forms/types/options/error_mapping.rst.inc b/reference/forms/types/options/error_mapping.rst.inc
index 5be15490508..1d71c390bf3 100644
--- a/reference/forms/types/options/error_mapping.rst.inc
+++ b/reference/forms/types/options/error_mapping.rst.inc
@@ -34,7 +34,14 @@ Here are the rules for the left and the right side of the mapping:
   object, the property path is ``[indexName]``;
 * You can construct nested property paths by concatenating them, separating
   properties by dots. For example: ``addresses[work].matchingCityAndZipCode``;
-* The left side of the error mapping also accepts a dot ``.``, which refers
-  to the field itself. That means that any error added to the field is added
-  to the given nested field instead;
 * The right side contains simply the names of fields in the form.
+
+Additionally, you can set the left side to dot (``.``), which refers to any
+unmapped property or method needing validation to the given nested field instead
+of bubbling them to the form::
+
+    $resolver->setDefaults(array(
+        'error_mapping' => array(
+            '.' => 'city',
+        ),
+    ));