diff --git a/Doc/library/winsound.rst b/Doc/library/winsound.rst
index f9709fe..b4a3391 100644
--- a/Doc/library/winsound.rst
+++ b/Doc/library/winsound.rst
@@ -30,8 +30,9 @@
    Call the underlying :cfunc:`PlaySound` function from the Platform API.  The
    *sound* parameter may be a filename, audio data as a string, or ``None``.  Its
    interpretation depends on the value of *flags*, which can be a bitwise ORed
-   combination of the constants described below.  If the system indicates an error,
-   :exc:`RuntimeError` is raised.
+   combination of the constants described below. If the *sound* parameter is
+   ``None``, any currently playing waveform sound is stopped. If the system
+   indicates an error, :exc:`RuntimeError` is raised.
 
 
 .. function:: MessageBeep([type=MB_OK])
@@ -108,6 +109,10 @@
 
    Stop playing all instances of the specified sound.
 
+   .. note::
+
+      This flag is not supported on modern Windows platforms.
+
 
 .. data:: SND_ASYNC