Supposedly, players aren't allowed to insert a faction of an allegiance that doesn't already exist in the system. Sometimes it even goes as far as being able to only choose the allegiance of the currently controlling faction.
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So, it shouldn't happen but it does happen. Great.
However, there seem to be a couple of people within the team that haven't got the memo. If you're lucky enough to have them processing your request, boom, anything you wish for. Imperial faction 30 ly from Sol or Lave? Done, no problem! (those actually exist)
Codorain used to be an Empire system "near" Lave (including lore blurb). There are still two Empire systems that got flipped by Codorain Empire faction.
Not exactly sure if a Fed PMF got placed in there of if a PMF expanded into it.
BD-22 3447 apparently got an Alliance PMF inserted. I'm not aware that an other Alliance faction expand into that system before.
Buthas got an Empire PMF with the next Empire system being in the Codorain region.
(Yea, I wondered why AEDC didn't apply for a PMF near Ross 128 - thought you guys'n'gals are just fair players. Form DNA-Decays comment it looks like at least the thought came into your minds