alt Hacker News"Junior" might be associated with poor or rural people, but "III" and "IV" can only convey the absolute maximum level of pompousness.
(There was a brief period where my sister was dating someone who went by J.T. The initials were something of an effort to obscure his name, James III.)
I've known two people in my life who went by some version of Trey as a nickname, as in some slight change if tres, three.