Issue #12245: Document sys.float_info.rounds better.
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 80f4cd7..a8b62da 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -328,8 +328,12 @@
+---------------------+----------------+--------------------------------------------------+
| :const:`radix` | FLT_RADIX | radix of exponent representation |
+---------------------+----------------+--------------------------------------------------+
- | :const:`rounds` | FLT_ROUNDS | constant representing rounding mode |
- | | | used for arithmetic operations |
+ | :const:`rounds` | FLT_ROUNDS | integer constant representing the rounding mode |
+ | | | used for arithmetic operations. This reflects |
+ | | | the value of the system FLT_ROUNDS macro at |
+ | | | interpreter startup time. See section 5.2.4.2.2 |
+ | | | of the C99 standard for an explanation of the |
+ | | | possible values and their meanings. |
+---------------------+----------------+--------------------------------------------------+
The attribute :attr:`sys.float_info.dig` needs further explanation. If