Sorry. I picked it up on some other online forum-type-thing. It basically means I know it isn't a random selection of people but for this comment it might as well be and I'm too lazy to look up what the actual allocation method is and add it as a footnote.
Why did you put an asterisk after "randomly", but not put an associated footnote in?
I've seen this a few times recently, on here, and don't understand the significance.