Mention the helper along with pip's deprecation policy
@@ -211,6 +211,12 @@ document existing behavior with the intention of covering that behavior with
the above deprecation process are always acceptable, and will be considered on
their merits.
+.. note::
+
+ pip has a helper function for making deprecation easier for pip maintainers.
+ The supporting documentation can be found in the source code of
+ ``pip._internal.utils.deprecation.deprecated``. The function is not a part of
+ pip's public API.
Release Process
===============
