you have to get two head shots in one shot.
To unlock ghille suits: winter-50 one shot kills, urban-100 one shot kills, and desert-150 one shot kills
get one-shot-kills with a sniper to unlock
You need 250 kills for the silver one gold I have NO IDEA
Get 50 one-shot kills with a sniper rifle.
You need to get "specre VII" I think that's like 1000 AC130 kills, when you get the gloden AC130 title you also get the spinning 10th prestige emblem from modern warfare one.
Which one?Gold: unlock all attachmentsGrey/Silver: 500 kills (need to be prestige)Grey/Silver with headshot icon: 250 headshotsWhite Skulls: 2500 killsGold Skulls: 1000 headshotscheck here for all the titles and emblems: http://callofduty.wikia.com/wiki/CallsignsYou have to get 10000 kills with the intervention.
Get 3 kills in one life with your secondary weapon
you have to get 250 knifing kills in one prestige.
You prestige one and then you get ten knife kills
You have to unlock one and quickly choose the "Use Title" button on the notification before it disappears
Get 750 kills while using One Man Army.
Depends if you can kill more people in one go.. but i went for the AC130 that's my best killstreak :) 11 kills with hardline 10 kills