Issue #9343: Document that argparse parent parsers must be configured before their children.
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index 102b3e9..2164ec0 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -351,6 +351,11 @@
:class:`ArgumentParser` will see two ``-h/--help`` options (one in the parent
and one in the child) and raise an error.
+.. note::
+ You must fully initialize the parsers before passing them via ``parents=``.
+ If you change the parent parsers after the child parser, those changes will
+ not be reflected in the child.
+
formatter_class
^^^^^^^^^^^^^^^