## Minimum requirements
The ECMAScript target version has been increased to es2019 from es2017.
+
+## Subscribe Button (WCF.User.ObjectWatch.Subscribe)
+
+We have replaced the old jQuery-based `WCF.User.ObjectWatch.Subscribe` with a more modern replacement `WoltLabSuite/Core/Ui/User/ObjectWatch`.
+
+The new implementation comes with a ready-to-use template (`__userObjectWatchButton`) for use within `contentInteractionButtons`:
+```smarty
+{include file='__userObjectWatchButton' isSubscribed=$isSubscribed objectType='foo.bar' objectID=$id}
+```
+
+See [WoltLab/WCF#4962](https://github.com/WoltLab/WCF/pull/4962/) for details.