The amount of money that Bob has earned since you last collected. I can't recall the exact amount but 1 dot is something like 0-50,000 cr 2 dot 50,000-150,000 and 3 dot is 150,000 and above or something around there.
I don't know if this is accurate, but I did read in the B-Spec forum that they can indeed hold 20 mil each. I don't recall if they said if they can hold more than that.
Some players were using them as bank accounts to have 140 mil total. 6 Bobs + self.