  * **admin.E026**: The value of ``prepopulated_fields`` must be a dictionary.
  * **admin.E027**: The value of ``prepopulated_fields`` refers to
    ``<field name>``, which is not an attribute of ``<model>``.
  * **admin.E028**: The value of ``prepopulated_fields`` refers to
    ``<field name>``, which must not be a ``DateTimeField``, ``ForeignKey`` or
    ``ManyToManyField``.
  * **admin.E029**: The value of ``prepopulated_fields[<field name>]`` must be a
    list or tuple.
  * **admin.E030**: The value of ``prepopulated_fields`` refers to
    ``<field name>``, which is not an attribute of ``<model>``.
  * **admin.E031**: The value of ``ordering`` must be a list or tuple.
 
</s> remove   be a ``ManyToManyField``.
 </s> add   be a many-to-many field. </s> remove * **admin.E003**: The value of ``raw_id_fields[n]`` must be a ``ForeignKey`` or
  ``ManyToManyField``.
 </s> add * **admin.E003**: The value of ``raw_id_fields[n]`` must be a foreign key or
  a many-to-many field. </s> remove   ``ManyToManyField``.
 </s> add   many-to-many field. </s> remove   ``ManyToManyField`` ``<field name>``, because that field manually specifies a
 </s> add   many-to-many field ``<field name>``, because that field manually specifies a </s> remove   ``ForeignKey`` or ``ManyToManyField``.
 </s> add   foreign key or a many-to-many field.
  ``<field name>``, which must not be a ``DateTimeField``, a foreign key or a
  many-to-many field.
  * **admin.E026**: The value of ``prepopulated_fields`` must be a dictionary.
  * **admin.E027**: The value of ``prepopulated_fields`` refers to
    ``<field name>``, which is not an attribute of ``<model>``.
  * **admin.E028**: The value of ``prepopulated_fields`` refers to
  ``<field name>``, which must not be a ``DateTimeField``, a foreign key or a
  many-to-many field.
  ``<field name>``, which must not be a ``DateTimeField``, a foreign key or a
  many-to-many field.
  * **admin.E029**: The value of ``prepopulated_fields[<field name>]`` must be a
    list or tuple.
  * **admin.E030**: The value of ``prepopulated_fields`` refers to
    ``<field name>``, which is not an attribute of ``<model>``.
  * **admin.E031**: The value of ``ordering`` must be a list or tuple.
keep keep keep keep replace replace keep keep keep keep keep
 Refs #24227 -- Replaced M2M isinstance checks by field.many_to_many

Thanks Markus Holtermann, Collin Anderson and Tim Graham for the reviews. 
docs/ref/checks.txt