Asus P9D-MH/SAS/10G-DUAL - Manual (Page 44)

2-24 Chapter 2: Hardware information
5. Location LED (LOCLED1)
The Location LED is an onboard LED that ligths up when the Location Button on the
front panel is pressed. This LED helps you visually locate the server among other
servers especially when you are located at the back of the server rack.
6. RLED (RLED1)
This LED lights up to indicate that the LSI 2308 is working properly. If the LED is unlit,
the LSI 2308 is either in fault state or a problem have occurred.