Document the 'n' integer presentation type for str.format().
diff --git a/Doc/library/string.rst b/Doc/library/string.rst
index 99c2c80..461f466 100644
--- a/Doc/library/string.rst
+++ b/Doc/library/string.rst
@@ -383,6 +383,10 @@
| ``'X'`` | Hex format. Outputs the number in base 16, using upper- |
| | case letters for the digits above 9. |
+---------+----------------------------------------------------------+
+ | ``'n'`` | Number. This is the same as ``'d'``, except that it uses |
+ | | the current locale setting to insert the appropriate |
+ | | number separator characters. |
+ +---------+----------------------------------------------------------+
| None | the same as ``'d'`` |
+---------+----------------------------------------------------------+