Luck RunesFollow

I know many of you have seen them, but I was wondering if anyone knew what Luck Runes are for. I'm talking about the spots like ??? found throughout various zones. So far I remember seeing them in Lufaise Meadows, in Yuhtunga Jungle as you drop on your way to Yhoatar, and in Xacabard near one of the G2 mobs. I know I have seen others as well. Is this part of some CoP quest or mission? Or is this a hidden element in FFXI. Any info would be appreciated.