Squad wipe - Kill 12 people from the same outfit
Kill trade - kill someone at the same time they have killed you. (+-2sec)
Can't think of an interesting name for this one - Kill someone then get killed by their proxy mine
I regret nothing - Kill two team mates and one enemy at roughly the same time. (=-5sec)
Don't stand in my way - Kill one team mate and two enemies at roughly the same time (+-5sec)