Just for the record, I published this in the Spectrum feedback section of the Spectrum forum a month ago. I sure hope Turbulent acts on it.
The Contact List might be used in game to better arrange groupings of players or accept missions. You are working on something along those lines already, I think. Great! Perhaps an Anti-Contact List would also be helpful but to do the opposite.
Players on a Contact List would receive a reputation boost relative to yourself. Players on an Anti-Contact List would receive a diminished reputation relative to yourself.
Both contact lists could be built from an option in-game and from Spectrum. There are so many unsavory players who present themselves in the Spectrum forum, especially lately. It would be nice to have a way to avoid having to play with them in game, too. Plus, there are a great many exemplary backers that I would love to have a greater chance of interacting with inside the game.
Hopefully, blocking will come to Spectrum. Blocking could be a way to populate, innocuously, the Anti-Contact List. BUT, I think a preferred way would be to have an Anti-Contact button within Spectrum itself. Also a Contact button in Spectrum. Coincidental Contacts (probably just from the Contact List) could populate an automatic Standard Contact List (as exists in-game now) and help bring people together.
The Anti-Contact List would greatly mitigate the desire for a PvP Slider ... which is not really an elegant solution to anything.
A Contact List is, of course, only relative to yourself. This makes trading or meeting people you respect easier and more favorable in-game. An Anti-Contact List is also only relative to yourself. This makes meeting those less savory, less likely. At the moment we have no way of carrying knowledge of reprehensible characters into the game; or, of those we greatly respect.
I may have refined my thinking on it a bit but the thought remains the same ... to reduce our having to play with ass-hats. Or more correctly, emotionally equivalent players will gravitate toward each other in-game and be able to avoid people of differing attitudes if they choose.