[2.0.x] Fixed #28761 -- Documented how an inline formset's prefix works.

Backport of 56e590cc0be4d8c8b6fe0967583a6e02d18ee03e from master

1 files changed, 4 insertions, 0 deletions

diff --git a/docs/topics/forms/modelforms.txt b/docs/topics/forms/modelforms.txt
index 1969474b89..a35f005877 100644
--- a/docs/topics/forms/modelforms.txt
+++ b/docs/topics/forms/modelforms.txt
@@ -1143,6 +1143,10 @@ a particular author, you could do this::
     >>> author = Author.objects.get(name='Mike Royko')
     >>> formset = BookFormSet(instance=author)
 
+``BookFormSet``'s :ref:`prefix <formset-prefix>` is ``'book_set'``
+(``<model name>_set`` ). If ``Book``'s ``ForeignKey`` to ``Author`` has a
+:attr:`~django.db.models.ForeignKey.related_name`, that's used instead.
+
 .. note::
 
     :func:`~django.forms.models.inlineformset_factory` uses