Ticket #11674: 11674.diff

docs/topics/forms/modelforms.txt

@@ -328 +328 @@
 
     If you specify ``fields`` or ``exclude`` when creating a form with
     ``ModelForm``, then the fields that are not in the resulting form will not
-    be set by the form's ``save()`` method. Django will prevent any attempt to
-    save an incomplete model, so if the model does not allow the missing fields
-    to be empty, and does not provide a default value for the missing fields,
-    any attempt to ``save()`` a ``ModelForm`` with missing fields will fail.
-    To avoid this failure, you must instantiate your model with initial values
-    for the missing, but required fields::
+    be set by the form's ``save()`` method. Also, should you manually add the
+    excluded fields back to the form, they will not be initialized from the
+    model instance.
 
+    Regarding the first remark, Django will prevent any attempt to save an
+    incomplete model, so if the model does not allow the missing fields to be
+    empty, and does not provide a default value for the missing fields, any
+    attempt  to ``save()`` a ``ModelForm`` with missing fields will fail.  To
+    avoid this failure, you must instantiate your model with initial values for
+    the missing, but required fields::
+
         author = Author(title='Mr')
         form = PartialAuthorForm(request.POST, instance=author)
         form.save()
@@ -628 +632 @@
 instance won't be saved to the database and won't be included in the return
 value (``instances``, in the above example).
 
+When fields are missing from the form, for example because they have been
+excluded, these fields will not be set by the ``save()`` method. You can find
+more information about this restriction, which also holds for regular
+``ModelForms``, and its consequences in section `Using a subset of fields on
+the form`_ of the ``ModelForms`` documentation.
+
 Pass ``commit=False`` to return the unsaved model instances::
 
     # don't save to the database