Serial library documentation misleading

From: http://arduino.cc/en/Reference/Serial

To use them to communicate with an external serial device, connect the TX pin to your device's RX pin, the RX to your device's TX pin, and the ground of your Mega to your device's ground.

This is a little misleading - it won't work, for example, with a serial device with RS232 levels, and may do some damage.

Thanks, I tried to clarify this.