diff --git a/README.md b/README.md
index a8abe7a..f153686 100644
--- a/README.md
+++ b/README.md
@@ -91,6 +91,7 @@ option to false.
 	   'height':'100px',
 	   'width':'300px',
 	   'interactive':true,
+	   'unique': true,
 	   'defaultText':'add a tag',
 	   'onAddTag':callback_function,
 	   'onRemoveTag':callback_function,