[LWalk18]

Since his name is Barack Hussein Obama, II, rather than Jr., his parents were not married at the time of his birth.

I have never heard of that distinction before- where is it written that someone with a Roman Numeral in his name is illegimate?

[MediaMole]

From my understanding, from III and up, it is not indicative of anything, but using II rather than Jr. indicates one of two things — illegitimacy or that a child was named for a close, living relative who was not his father.