If I define a Django model with a recursive relationship as follows,
Class M(models.Model):
a = models.CharField(max_length=1)
ms = models.ManyToManyFied('self')
and in the admin site I enter data such afterwards M.a = 'a','b', and 'c'. The Django admin site's change form will show ms to contain 'a', 'b', 'c'. How do I remove 'a' from the list since I don't want it assigned to current M.a which is itself?