Allows users to delete their thread rating on a thread if they've previously rated it (set as a usergroup permission).

To undo your rating, just click the Undo Rating link next the rating stars on a thread page (link will only show if the user has previously rated). Currently this does not support guests undoing their ratings.

The usergroup permission are located under the Posting/Rating Options? section of the 'Forums and Posts' tab when editing a usergroup. This plugin offers full language support.