#2476: document that %default feature is new in 2.4.
diff --git a/Doc/library/optparse.rst b/Doc/library/optparse.rst
index 68b5709..d72e387 100644
--- a/Doc/library/optparse.rst
+++ b/Doc/library/optparse.rst
@@ -534,10 +534,11 @@
description "write output to FILE". This is a simple but effective way to make
your help text a lot clearer and more useful for end users.
-* options that have a default value can include ``%default`` in the help
- string---\ :mod:`optparse` will replace it with :func:`str` of the option's
- default value. If an option has no default value (or the default value is
- ``None``), ``%default`` expands to ``none``.
+.. versionadded:: 2.4
+ Options that have a default value can include ``%default`` in the help
+ string---\ :mod:`optparse` will replace it with :func:`str` of the option's
+ default value. If an option has no default value (or the default value is
+ ``None``), ``%default`` expands to ``none``.
When dealing with many options, it is convenient to group these
options for better help output. An :class:`OptionParser` can contain