Killzone 2 Unlocks - I keep looking this stuff up so here it is!

I keep trying to figure out what I have to or want to work on next to unlock certain things - here's a nice break down. I want C4 next but I think I am really close to unlocking my secondary medic badge so I guess I should run around healing people for a couple of matches first and then work on the C4.

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• Elite mode
  Successfully complete Story mode to unlock the Elite difficulty.
  

• Ribbons
  Successfully complete the indicated task to get the corresponding Ribbon:
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
   
  
• • Air Support Specialist: Get five kills by air support.
• • Assassination Defend Specialist: Stay alive as an assassination target.
• • Assassination Kill Specialist: Kill one assassination target.
• • Body Count Specialist: Get 10% of the kills for your team in the "Body Count" mission.
• • Boost Specialist: Perform five boosts.
• • C4 Specialist: Perform five kills with C4 explosives.
• • Capture and Hold Defend Specialist: Get ten mission points by capturing a point.
• • Cloak Specialist: Kill five enemies while cloaked.
• • Close Combat Specialist: Get ten kills by close combat melee.
• • Disguise Specialist: Kill five enemies while disguised.
• • Good Conduct: Get no team kills/suicides, and score at least 20 points.
• • Headshot Specialist: Get ten kills by headshots.
• • Healing Specialist: Heal five players.
• • Kill Count Specialist: Get ten kills in one round.
• • Repair Specialist: Repair five objects.
• • Revival Specialist: Successfully revive five players.
• • Search and Destroy Specialist: Have two objectives placed/disarmed.
• • Search and Retrieve Specialist: Have two objectives returned.
• • Sidearm Specialist: Get ten kills with pistols.
• • Sniper Specialist: Get ten kills with the sniper rifle.
• • Spawn Point Specialist: Have five players spawn in the placed area.
• • Spot and Mark Specialist: Spot and mark five players.
• • Turret Specialist: Get five kills with sentry turret placed.

• Medals
  Successfully complete the indicated task to earn the corresponding medal:
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
   
  
• • Aerial Supportive: 8x Air Support Specialist Ribbons; unlocks Combine Tactician second Ability.
• • Army Superior Unit Award: 50x Clan matches won with Clan; unlocks 100,000 Valor.
• • Assassins League: 5x Assassination Kill Specialist Ribbons; unlocks Increased Points/Assassination Kills.
• • Black Belt: 5x Close Combat Specialist Ribbons; unlocks Increased Points/Melee Kill.
• • Bodyguard Alliance: 5x Assassination Defend Specialist Ribbons; unlocks Increased Points per Survival.
• • Bomb Squad: 5x Search and Destroy Specialist Ribbons; unlocks Increased Points/Returns/Disarms.
• • Corpse Counters: 5x Body Count Specialist Ribbons; unlocks Increased Points/Defensive Kills.
• • Defense Initiative: 5x Capture and Hold Defend Specialist Ribbons; unlocks Increased Points/Defensive Kills.
• • Defensive Specialist Ribbons: 8x Turret Specialist Ribbons; unlocks second Engineer Ability.
• • Example Soldier: 8x Good Conduct Ribbons; unlocks Increased Start Ammo Amount.
• • Explosives Expert: 8x C4 Specialist Ribbons; unlocks Combine Saboteur second Ability.
• • Field Mechanic: 8x Repair Specialist Ribbons; unlocks Combine Engineer second Ability.
• • Field Medic: 8x Healing Specialist Ribbons; unlocks Combine Medic second Ability.
• • Forward Observer: 8x Spot and Mark Specialist Ribbons; unlocks Combine Scout second Ability.
• • Front Runner: 8x Boost Specialist Ribbons; unlocks Combine Assault second Ability.
• • Hawk's Eye: 5x Sniper Specialist Ribbons; unlocks Second Sniper Zoom.
• • Head Fetish: 5x Headshot Specialist Ribbons; unlocks Increased Points/Headshot.
• • Master of Disguise: 8x Disguise Specialist Ribbons; unlocks Saboteur Ability.
• • Meritorious Unit Award: 10x Clan matches won with Clan; unlocks 1000 Valor.
• • Meritorious Unit Award: 25x Clan matches won with Clan; unlocks 10,000 Valor.
• • Natural Born Killer: 8x Kill Count; unlocks Increased Grenade Amount.
• • Quick Draw: 5x Sidearm Specialist Ribbons; unlocks M4 Revolver second weapon.
• • Retrieval Corps: 5x Search and Retrieve Specialist Ribbons; unlocks Increased Points/Return.
• • Shadow Marshall: 8x Cloak Specialist Ribbons; unlocks second Scout Ability.
• • Spawn Authority: 8x Spawn Point Specialist Ribbons; unlocks second Tactician Ability.
• • Trauma Surgeon: 8x Revival Specialist Ribbons; unlocks second Medic Ability.

• Rank bonuses
  Earn more points and get a higher "difference" score to unlock higher ranks and their corresponding bonuses:
  
  
  
  
  
  
  
  
               Lieutenant-Colonel: 1,850 points, 400 difference; unlocks grenade launcher. 
  
  
  
   
  
• • Corporal: 30 points, 30 difference; can create Squad option.
• • Sergeant: 100 point, 70 difference; can create Clan option.
• • Sergeant 1st Class: 200 points, 100 difference; unlocks Shotgun and SMG.
• • Master Sergeant: 350 points, 150 difference; unlocks Medic Badge.
• • Sergeant Major: 550 points, 250 difference; unlocks HGH and ISA LMG.
• • Lieutenant: 880 points, 250 difference; unlocks Engineer Badge.
• • Captain: 1,100 points, 300 difference; unlocks VC9 missile launcher.
• • Major: 1,450 points, 350 difference; unlocks Tactician Badge.
• • Colonel: 2,300 points, 450 difference; unlocks Saboteur Badge.
• • General: 2,800 points, 500 difference; unlocks Scout Badge.