diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index a33e796..09a987c 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -883,6 +883,10 @@
 
    .. versionadded:: 3.3
 
+   .. note::
+
+      The addition of new required attributes must go through the normal PEP
+      process. See :pep:`421` for more information.
 
 .. data:: int_info
 
diff --git a/Misc/NEWS.d/next/Documentation/2019-07-13-12-58-20.bpo-37284.rP8WpB.rst b/Misc/NEWS.d/next/Documentation/2019-07-13-12-58-20.bpo-37284.rP8WpB.rst
new file mode 100644
index 0000000..f875791
--- /dev/null
+++ b/Misc/NEWS.d/next/Documentation/2019-07-13-12-58-20.bpo-37284.rP8WpB.rst
@@ -0,0 +1 @@
+Add a brief note to indicate that any new ``sys.implementation`` required attributes must go through the PEP process.
\ No newline at end of file