relationships, but if you want to add other models in, simply pass ``--freeze appname``
to the ``./manage.py datamigration`` command.
+Also note that the ``backwards()`` method gets the ORM as frozen by the previous
+migration except for migrations that define ``symmetrical = True`` (new in South 1.0)
models = %(frozen_models)s
+ if getattr(self.migration_class(), 'symmetrical', False):
previous = self.previous()
# First migration? The 'previous ORM' is empty.