bpo-38623: Add note about site module (site-packages) (GH-16974)
diff --git a/Doc/tutorial/modules.rst b/Doc/tutorial/modules.rst
index a495c50..f1d4957 100644
--- a/Doc/tutorial/modules.rst
+++ b/Doc/tutorial/modules.rst
@@ -191,7 +191,8 @@
file is specified).
* :envvar:`PYTHONPATH` (a list of directory names, with the same syntax as the
shell variable :envvar:`PATH`).
-* The installation-dependent default.
+* The installation-dependent default (by convention including a
+ ``site-packages`` directory, handled by the :mod:`site` module).
.. note::
On file systems which support symlinks, the directory containing the input
