def tags(self):
        """Returns a dictionary that lists all available tags that can be used
        for further filtering
        """
        ret = {}
        for typ in _meta_fields_twig:
            if typ in ['uniqueid', 'plugin', 'feedback', 'fitting', 'history', 'twig', 'uniquetwig']:
                continue

            k = '{}s'.format(typ)
            ret[k] = getattr(self, k)

        return ret