[#2023] Adding a missing versionadded

weaverryan · weaverryan · commit 4a538777e641 · 2012-12-17T21:27:35.000-06:00
diff --git a/reference/constraints/Luhn.rst b/reference/constraints/Luhn.rst
@@ -1,6 +1,9 @@
 Luhn
 ======
 
+.. versionadded:: 2.2
+    The Luhn validation is new in Symfony 2.2.
+
 This constraint is used to ensure that a credit card number passes the `Luhn algorithm`_.
 It is useful as a first step to validating a credit card: before communicating with a
 payment gateway.
