Well, Sov, I do know that when I get into open SP, and I set all factions to friendly, I can't buy faction IDs, only civilian and Recruit ones. Simple system, maybe, but, that's what I've noticed...
[8:32:45 PM] Dusty Lens: Oh no, let me get that. Hello? Oh it's my grandma. She says to be roleplay.
[12:49:19 AM] Elgatodiablo: You know its nice that you have all that proof and all, Bacon... but I just don't believe you.
It may depend on how friendly it sets you. Most factions require full rep (1.0, not .9 where the bars stop) before you can buy IDs there. Do missions, take double bribes, etc- see if that does it.