i9 know what the three enhancement slots are for!
 

I got this off the korean site and it should eventually come in a update

1. You can see 3 additional slots at the bottom of Item enhance window.
2. In these slots, you can put special items which can help you succeed item enhancement.
3. These are called red slot, gold slot and blue slot from the left, and applicable items are different.


Red Slot : You can put Red Eye and Perfect Red Eye on this slot, and these will prevent from failing
　　　　　to critical.
Gold Slot : You can put gold nine on this slot, and it will raise success rate of Item enhance.
Blue Slot : You can put Blue Mile and Perfect Blue Mile, and these will prevent from failing
　　　　　to downgrade.

YAY lower failure rate