bpo-40013: Clarify documentation of restval in csv.DictReader (GH-19099)
diff --git a/Doc/library/csv.rst b/Doc/library/csv.rst
index 49e22fa..61d3982 100644
--- a/Doc/library/csv.rst
+++ b/Doc/library/csv.rst
@@ -161,7 +161,8 @@
If a row has more fields than fieldnames, the remaining data is put in a
list and stored with the fieldname specified by *restkey* (which defaults
to ``None``). If a non-blank row has fewer fields than fieldnames, the
- missing values are filled-in with ``None``.
+ missing values are filled-in with the value of *restval* (which defaults
+ to ``None``).
All other optional or keyword arguments are passed to the underlying
:class:`reader` instance.