A9DA BIOS: What does "FORCE SATA RAID" do?

I have the A9DA AM3 MB from Foxconn, which includes an SB850 for the southbridge. I am wondering whether SATA ports 5 and 6 (eSATA) can be used in RAID arrays. The manual isn't very clear, but seems to indicate that these ports can only be used as IDE-compatible ports or not at all. But then there's this "FORCE SATA RAID" option in the BIOS. It isn't documented in the printed user manual (v 1.0) or in the most-recently-available downloadable user manual (which is apparently also v 1.0).

Does anyone know what that setting does? It is currently set to Disabled. Please note that this setting is not the one that switches (the other 4) SATA ports between IDE, AHCI and RAID mode. I am already using the other ports with a RAID array.

Just in case anyone ever wants to know: This setting appears to force the MB to use any attached HDDs that were configured as RAID arrays in their RAID array configuration. I can't be certain about this, but I had two 500 GB drives in RAID 1. I released the array in BIOS. I booted, and Windows recognized one of the drives, and said the other couldn't be used because of a duplicate identifier. OK. Reboot, set the SATA FORCE RAID setting (I had it backwards in the title), and go back into Windows. All of a sudden, a new device is found - the RAID 1 array comprising the two 500 GB drives. I suppose this is in case of MB failure or something so that you can recover your data, but strange nevertheless.

Next, I fiddled with the SATA IDE Combined Mode setting. Page 37 of the version 1 manual documents this as follows:

Note: The ESATA port is SATA 6 on this MB.
First, there are no PATA ports on this MB. Second, there is no "next 'Combined Mode Option' setting." Third, the "Disabled" option doesn't behave anything like what is described. Rather than disabling the ports, it makes them usable as part of a RAID array! Just what I wanted to do.

I suppose no one said that this MB manual was accurate, but geez this one is stupid-wrong.