to delete documents select one or more documents from the list and click on the button <delete> and confirm. the document gets transferred to the trash.

To restore a document from the trash, go to the trash and search for the document. over the context menu click on the item <restore>. the document gets restored to it's original folder.

If you want to delete the document permanently you have to delete it from the trash. but only a "admin" can empty the trash or delete an item from the trash.