Django mixin-model for audit stats

models.py

class AuditStatsModelMixin(models.Model):
    "audit metadata"
    created_on = models.DateTimeField(auto_now_add=True)
    created_ip = models.IPAddressField(null=True)
    created_by = models.ForeignKey(User, related_name="%(app_label)s_%(class)s_created_by")
    updated_on = models.DateTimeField(auto_now=True)
    updated_ip = models.IPAddressField(null=True)
    updated_by = models.ForeignKey(User, related_name="%(app_label)s_%(class)s_updated_by", null=True)

    class Meta:
        abstract = True

Is this a mixin?