Asus V3-P5G45 - Manual (Page 72)

4-12 Chapter 4: Motherboard info
8.. Chassis.intrusion.connector.(4-1.pin.CHASSIS)
This connector is for a chassis-mounted intrusion detection sensor or switch.
Connect one end of the chassis intrusion sensor or switch cable to this connector.
The chassis intrusion sensor or switch sends a high-level signal to this connector
when a chassis component is removed or replaced. The signal is then generated
as a chassis intrusion event.
By default , the pin labeled “Chassis Signal” and “Ground” are shorted with a
jumper cap. Remove the jumper caps only when you intend to use the chassis
intrusion detection feature.
9.. Digital.audio.connector.(4-1.pin.SPDIF_OUT)
This connector is for an additional Sony/Philips Digital Interface (S/PDIF)
port(s).
The S/PDIF out cable is purchased separately.