  above) be the name of the model, lowercase. You can, of course, call the field
  whatever you want. For example::
  
      class Car(models.Model):
          company_that_makes_it = models.ForeignKey(Manufacturer)
          # ...
  
  .. seealso::
  
      :class:`~django.db.models.ForeignKey` fields accept a number of extra
 
</s> remove         cat = models.ForeignKey(Category)
 </s> add         cat = models.ForeignKey(Category, models.CASCADE) </s> remove         manufacturer = models.ForeignKey(Manufacturer)
 </s> add         manufacturer = models.ForeignKey(Manufacturer, on_delete=models.CASCADE) </s> remove     parent = models.OneToOneField(Place)
 </s> add     parent = models.OneToOneField(Place, models.CASCADE) </s> remove     parent = models.ForeignKey(ParentWithDependentChildren)
 </s> add     parent = models.ForeignKey(ParentWithDependentChildren, models.CASCADE) </s> remove     poll = models.ForeignKey(Poll, verbose_name="the related poll")
 </s> add     poll = models.ForeignKey(
        Poll,
        on_delete=models.CASCADE,
        verbose_name="the related poll",
    )
        company_that_makes_it = models.ForeignKey(
            Manufacturer,
            on_delete=models.CASCADE,
        )
  above) be the name of the model, lowercase. You can, of course, call the field
  whatever you want. For example::
  
      class Car(models.Model):
        company_that_makes_it = models.ForeignKey(
            Manufacturer,
            on_delete=models.CASCADE,
        )
          # ...
  
  .. seealso::
  
      :class:`~django.db.models.ForeignKey` fields accept a number of extra
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
docs/topics/db/models.txt