Communication etiquette

Please, put more info in the tutorial about proper comms etiquette and the importance of communication. Maybe something about avoiding external voice and text chat also.

A few times now I've Swiss-cheesed a teammate because I saw a silhouette, asked on the radio if it was one of ours, and got silence. Couldn't chance it, so I took the shot, THEN they found their F key. Hit a friendly once because I set up some remote explosives out of view (that's the point of motion sensors, after all) and I had no idea where they were because no one said where they were going or what they were doing. I wasn't being careless, they were just using the voice chat to talk to their friends about TV shows instead of talking to their teammates about the objective.

This game really shines when people use the comms properly, but without communication, tactics go out the window and it's just another shooter. A little more info/emphasis in the tutorial might make this a little more clear.