Demo Specialist Beat Jaguar Maze on veteran while completing the extra objective.
Rifleman Specialist Beat Angel Rage on veteran while completing the extra objective.
Rifleman Specialist Beat Watchful Yeoman on veteran while completing the extra objective.
Rifleman Specialist Beat Rapid Puthon on veteran while completing the extra objective.
Sniper Specialist Beat Hidden Spectre on veteran while completing the extra objective.
Support Specialist Beat Liberty Storm on veteran while completing the extra objectives.

At the start screen enter L1, L1, L1, R1, R1, R1, R1 for a 12 Player Room (6 vs 6)

At the start screen enter R1,R1,L1,L1,R1,L1 Turns on voice chat in online game

At the start screen press R1, L1, L1, R1, R1, R1 to unlock all maps in quick mission

Enter this in the pause menu during the cuban operation L1, L2, R1, R2, X, Select to unlock all special features

Enter these at the start menu:
L1, R2, L2, R1, Select to get Invincibility
X, L2, Triangle, R2, Select to pick your mission
R1, L1, L1, R1, R1, R1 to unlock all maps in quick mission
R1, R1, R1, R1, X, O, L2+L1 Unlock all missions