Mine

from django.db import models

class Tag(models.Model):
        name=models.CharField(maxlength=30)

        def __str__(self):
                return self.name

        class Meta:
                ordering=('name')

class Article(models.Model):
        f=models.CharField(maxlength=100)
        tags=models.ManyToManyField(Tag)

        def __str__(self):
                return self.f

        class Meta:
                ordering=('f')