symfony · javiereguiluz · Aug 30, 2016 · Aug 30, 2016 · Aug 31, 2016 · Oct 4, 2016
diff --git a/reference/constraints/UniqueEntity.rst b/reference/constraints/UniqueEntity.rst
@@ -132,7 +132,18 @@ message

 **type**: ``string`` **default**: ``This value is already used.``

-The message that's displayed when this constraint fails.
+The message that's displayed when this constraint fails. This message is always
+mapped to the first field causing the violation, even when using multiple fields
+in the constraint.
+
+.. versionadded:: 3.1
+    The ability to include the invalid value into the message was introduced
+    in Symfony 3.1.
+
+Messages can include the ``{{ value }}`` placeholder to display a string
+representation of the invalid entity. If the entity doesn't define the
+``__toString()`` method, the following generic value will be used: *"Object of
+class __CLASS__ identified by <comma separated IDs>"*

 em
 ~~