#8213: document behavior of -u on py3k better.
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index 540e4d7..0978770 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -232,8 +232,9 @@
.. cmdoption:: -u
- Force stdin, stdout and stderr to be totally unbuffered. On systems where it
- matters, also put stdin, stdout and stderr in binary mode.
+ Force the binary layer of the stdin, stdout and stderr streams (which is
+ available as their ``buffer`` attribute) to be unbuffered. The text I/O
+ layer will still be line-buffered.
See also :envvar:`PYTHONUNBUFFERED`.