Looking for trigger conditions for certain achievements

[yoyoma]

Prevent FF 4 team kills

I'm probably overlooking something obvious, but what does "FF" stand for? I assume friendly fire, but I don't know how the API would determine that I've saved 4 people from being TK'd?

EDIT:
Also, just to be clear (I'm going through some custom voice pack stuff myself), the EXCELLENT/OUTSTANDING/SUPERB entries will play randomly every time you kill an enemy, provided you have the Sound Per Kill checked. True statement?

Thanks!