The first unmarked jumper bank was located at the top center (as the motherboard sits in the tower) of the board just above the processor socket which had no reference in the manual for it that I could find. It was labeled on the motherboard: Overvolt
The choices were:
1-2 Enabled
3-4 Disabled
Counting left to right, pins 1-2-3
This would appear to be an overclocking feature that allows for higher voltage than normal when placed in the enabled mode. Since I would never set up a motherboard for first boot with overclocking features enabled, I left it on the default, Disabled for now.
The second unmarked jumper bank was JP1 and JP2. There is a reference for these jumpers on page 8 of the manual but it is only a location picture. The jumpers are designed to allow for memory voltage to be increased in overclocking and as noted above in another post, Asus has changed their default factory setting for this jumper to pins 1-2 for both banks. In the past it was 1-2 for JP1 and 2-3 for JP2. Be aware of that.