diff --git a/docs/ref/contrib/admin/_images/raw_id_fields.png b/docs/ref/contrib/admin/_images/raw_id_fields.png
new file mode 100644
index 0000000000..0774c40469
Binary files /dev/null and b/docs/ref/contrib/admin/_images/raw_id_fields.png differ
diff --git a/docs/ref/contrib/admin/index.txt b/docs/ref/contrib/admin/index.txt
index 6fc88cc135..c403541129 100644
--- a/docs/ref/contrib/admin/index.txt
+++ b/docs/ref/contrib/admin/index.txt
@@ -814,6 +814,14 @@ subclass::
         class ArticleAdmin(admin.ModelAdmin):
             raw_id_fields = ("newspaper",)
 
+    The ``raw_id_fields`` ``Input`` widget should contain a primary key if the
+    field is a ``ForeignKey`` or a comma separated list of values if the field
+    is a ``ManyToManyField``.  The ``raw_id_fields`` widget shows a magnifying
+    glass button next to the field which allows users to search for and select
+    a value:
+
+    .. image:: _images/raw_id_fields.png
+
 .. attribute:: ModelAdmin.readonly_fields
 
     .. versionadded:: 1.2