This is rather simple to accomplish, but I still wanted to share the idea with you guys. You know how in EVN you're able to fly from the Federation to Auroran territory unchallenged? (If you have good ratings in both territories.) I decided that in an actual situation far into the future with ships that have superluminal flying capabilities that the governments formed would want the ships coming into their territory to show or buy passports from them in order to keep track of who's coming in and out of your territory. We can do this in EVN using some trickery with governments and ranks.
Let's say you have two factions with systems in their domains and a central government. We'd make four govt resources, two for each faction; one govt would be friendly towards the player when he/she didn't have a passport and one would attack the player when he/she didn't have a passport. We'd place the government that was friendly towards the player all the time in border systems where the player could buy a passport from either a station or a pers ship via a mission and the government that attacks players without passports in core systems so the player can't progress past the border systems without a passport.
Now, the passport would be a rank granted through the Kxxx command with either an outfit or a mission. Either way, the rank would have the ID of the govt the passport modifies in the government field and have the "This government will not attack the player" flag and the "Deactivate if the player commits a crime against this government" flag both checked. This way, the player will be let peacefully through this governments space and will be attacked if he/she tries to board/destroy a ship.
This could be modified so that the rank is deactivated when the player's legal record falls to a certain level with a mission or so that the player can't land on planets with a passport. (This would probably be more practical.)
I admit that the way governments would treat the player if he turned into a pirate is a little shaky with this method, but none-the-less comments and death threats are all welcome.