'Remove a tag from an item.'

def _remove_items_tag(self, trans, item_class_name, id, tag_name):

    user = trans.user
    tagged_item = self._get_tagged_item(trans, item_class_name, id)
    deleted = (tagged_item and self.get_tag_handler(trans).remove_item_tag(trans, user, tagged_item, tag_name))
    trans.sa_session.flush()
    return deleted
