It comes with User Search bar, so you can find and tag any user/guest very easy. It also displays #ID of each comment to let you tag them. All mentioned users and comment authors will be notified via email. This addon replace @author and #comment-id to links with avatars. It opens a pop-up window with user and comment information when you hover on @author and #comment-id links.
Please note: this is an add-on for wpDiscuz plugin. This addon requires at least wpDiscuz 4.0.0 version.