+use a tty
+.I line
+instead of a pseudo terminal.
+.I line
+should be a (pseudo-)serial device (e.g. /dev/ttyS0 on Linux for serial port
+0).
+When this flag is given
+remaining arguments are used as flags for
+.BR stty(1).
+By default st initializes the serial line to 8 bits, no parity, 1 stop bit
+and a 38400 baud rate. The speed is set by appending it as last argument
+(e.g. 'st -l /dev/ttyS0 115200'). Arguments before the last one are
+.BR stty(1)
+flags. If you want to set odd parity on 115200 baud use for example 'st -l
+/dev/ttyS0 parenb parodd 115200'. Set the number of bits by using for
+example 'st -l /dev/ttyS0 cs7 115200'. See
+.BR stty(1)
+for more arguments and cases.