Premade notification
If you are playing in a premade with friends, say so in the title of the game. It's unfair to PUGs to join a game against 3-4 players on voice comm cooperating against total strangers. It's an unfair advantage and really goes against the competitive spirit of the game.
I have friends I play with too but I let everyone know it's a premade and hopefully go up against stronger players or another premade for some competition. If you wanna steamroll over noobs with your buddies, Go comp stomp...