diff --git a/qemu-options.hx b/qemu-options.hx
index 484cc21c1f..40e938c487 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4129,7 +4129,8 @@ SRST
     This option can be used several times to simulate up to 4 serial
     ports.
 
-    Use ``-serial none`` to disable all serial ports.
+    You can use ``-serial none`` to suppress the creation of default
+    serial devices.
 
     Available character devices are:
 
@@ -4151,10 +4152,17 @@ SRST
         [Linux only] Pseudo TTY (a new PTY is automatically allocated)
 
     ``none``
-        No device is allocated.
+        No device is allocated. Note that for machine types which
+        emulate systems where a serial device is always present in
+        real hardware, this may be equivalent to the ``null`` option,
+        in that the serial device is still present but all output
+        is discarded. For boards where the number of serial ports is
+        truly variable, this suppresses the creation of the device.
 
     ``null``
-        void device
+        A guest will see the UART or serial device as present in the
+        machine, but all output is discarded, and there is no input.
+        Conceptually equivalent to redirecting the output to ``/dev/null``.
 
     ``chardev:id``
         Use a named character device defined with the ``-chardev``