The motherboard is compatible with either HD or AC97 audio to the front panel.
I took this pin out and extra information from the manual
For AC'97 Front Panel Audio:
• The front panel audio header supports HD audio by default. If your chassis provides an
AC'97 front panel audio module, refer to the instructions on how to activate AC'97 functioninality
via the audio software in Chapter 5, "Configuring 2/4/5.1/7.1-Channel Audio."
• Audio signals will be present on both of the front and back panel audio connections
simultaneously. If you want to mute the back panel audio (only supported when using an HD
front panel audio module), refer to Chapter 5, "Configuring 2/4/5.1/7.1-Channel Audio."
• Some chassis provide a front panel audio module that has separated connectors on each
wire instead of a single plug. For information about connecting the front panel audio
module that has different wire assignments, please contact the chassis manufacturer.
Pin No. Definition
1 MIC
2 GND
3 MIC Power
4 NC
5 Line Out (R)
6 NC
7 NC
8 No Pin
9 Line Out (L)
10 NC