Note that PEP 378 also applies to int.
diff --git a/Doc/whatsnew/2.7.rst b/Doc/whatsnew/2.7.rst
index e18db48..e0e4e0f 100644
--- a/Doc/whatsnew/2.7.rst
+++ b/Doc/whatsnew/2.7.rst
@@ -218,6 +218,11 @@
>>> '{:20,.2f}'.format(18446744073709551616.0)
'18,446,744,073,709,551,616.00'
+When formatting an integer, include the comma after the width:
+
+ >>> '{:20,d}'.format(18446744073709551616)
+ '18,446,744,073,709,551,616'
+
This mechanism is not adaptable at all; commas are always used as the
separator and the grouping is always into three-digit groups. The
comma-formatting mechanism isn't as general as the :mod:`locale`