Issue 5150: Add rstrip() menu option to IDLE.
diff --git a/Doc/whatsnew/3.1.rst b/Doc/whatsnew/3.1.rst
index ace8c3f..c34a91c 100644
--- a/Doc/whatsnew/3.1.rst
+++ b/Doc/whatsnew/3.1.rst
@@ -470,6 +470,14 @@
 
   (Contributed by Jake McGuire and Antoine Pitrou; :issue:`5084`.)
 
+IDLE
+====
+
+* IDLE's format menu now provides an option to strip trailing whitespace
+  from a source file.
+
+  (Contributed by Roger D. Serwy; :issue:`5150`.)
+
 Build and C API Changes
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