Demote warnings to notices where appropriate, following the goal that as few "red box" warnings
should clutter the docs as possible.  Part 1: stuff that gets merged to Py3k.
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index 685e941..c95566b 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -301,10 +301,10 @@
 
 .. warning::
 
-   Use :meth:`communicate` rather than :meth:`.stdin.write`,
-   :meth:`.stdout.read` or :meth:`.stderr.read` to avoid deadlocks due
-   to any of the other OS pipe buffers filling up and blocking the child
-   process.
+   Use :meth:`communicate` rather than :attr:`.stdin.write <stdin>`,
+   :attr:`.stdout.read <stdout>` or :attr:`.stderr.read <stderr>` to avoid
+   deadlocks due to any of the other OS pipe buffers filling up and blocking the
+   child process.
 
 
 .. attribute:: Popen.stdin