Zoners are space libertarians that set up a confederation of freeports and then promptly diplomaticized everything so they wouldn't get shot at. Then, evil SPESS EMPIRES happened, and we had military patrols saying hi. The Zoners said "This is our space because we're here and have turrets. 22 of them." and the Houses were all "cool" and all was dandy. Then Zonerzonerzoner happened, because, well, because. The main thing is that Zoners are officially "their own territory, and the Houses have historically been cool with that".
An example would not be amiss here.
You have a system that's pretty much rocks and rocks. No claimable resources. Nothing. It happens to be in independent space. That's an ideal location for a Zoner freeport, and that's what they were. Suddenly, 20 years pass, and people want to expand into independent space. Oh hi. Zoners are all "Oh goody, people again. Hit the showers, folks."
Surprise, surprise, a bit of war happens, and the gates are blown.
Now the place is a backwater that has literally nothing to offer but a slip through to that place, which is offered in two systems. No Guard system access, no nothing. It's as backwater as a backwater can get, and that's the way they like it.
Bam, the tale of Freeport 2 in a nutshell.
Another example:
Builds a space station in the middle of nowhere. Is Zoner. Suddenly, Corsairs. Corsairs are "Oh, cool." about this, and occasionally buy food from these guys for Crete. Oh, and the odd "Okay, drop the cargo. You've got loot and I want it now." A little while later, the Corsairs start getting eaten by Bounty Hunters. They find the Freeport crawling with them. And they can't do a thing about it, because of all the other people with a vested interest in the place.
Freeport 9 diplomacy.
The average Zoner Juggernaut:
It's a giant colony ship that's very well-armed because NOMADS. ARE. OUT. THERE. Especially where they might want to settle. It's also expensive as hell because, fluff-wise, there are only a few of them out there, mostly because the one Zoner shipyard is in the middle of nowhere, and is in a bloody asteroid field. This is moot from a meta perspective because powertrading lets people buy capships on a lark, but in-universe, it's a hard to supply base that makes colony vessels and Q-ships.
(Remember 4.84? I got a Zoner Juggernaut from Livadia and literally could not get it out of the field because of dem wings. Also, the 4.84 Liberty Carrier back when it was sold at Norfolk looked amazing.)