all other arguments and does not configure the port. This may be
useful for special serial ports such as Bluetooth-to-serial converters
which can only be configured through AT commands sent through the
-connection. You can use the value of @code{nil} for @var{speed} only
-for connections that are already open by a previous call to
+connection. The value of @code{nil} for @var{speed} is valid only for
+connections that were already opened by a previous call to
@code{make-serial-process} or @code{serial-term}.
@item :bytesize @var{bytesize}