[doc] Link to deprecation policy PEP from the DeprecationWarning documentation (GH-28123) (GH-28124)

miss-islington · ambv · web-flow · commit ca27109c17df · 2021-09-02T17:14:11.000+02:00
(cherry picked from commit a7ef15a) Co-authored-by: Łukasz Langa <lukasz@langa.pl>
diff --git a/Doc/library/exceptions.rst b/Doc/library/exceptions.rst
@@ -717,6 +717,8 @@ The following exceptions are used as warning categories; see the
    (:pep:`565`). Enabling the :ref:`Python Development Mode <devmode>` shows
    this warning.
 
+   The deprecation policy is described in :pep:`387`.
+
 
 .. exception:: PendingDeprecationWarning
 
@@ -731,6 +733,8 @@ The following exceptions are used as warning categories; see the
    Ignored by the default warning filters. Enabling the :ref:`Python
    Development Mode <devmode>` shows this warning.
 
+   The deprecation policy is described in :pep:`387`.
+
 
 .. exception:: SyntaxWarning
 
