In Modern Warfare 3, I've seen many people that have what seems to be a fourth perk when I've been killed by them. Listed under the 3 regular perks (the coloured ones) there is a fourth icon that is always coloured white.
I've seen a few different ones (can't remember the names off the top of my head).
What are they, and how do I unlock them?
Best Answer
This indicates their weapon proficiency. You unlock weapon proficiencies by gaining weapon experience getting kills with that weapon. This will unlock proficiencies such as Impact, Focus or the ability to use two Attachments.