Here is a full listing of the current pins in Battlefield 2142 as well as the requirements needed to receive them.
IASR = In A Single Round
Combat Efficiency Pin

- IASR: 5 Kill Streak
Distinguished Combat Efficiency Pin

- IASR: 10 Kill Streak
Problem Solver Pin

- IASR: 4 Titan Consoles Destroyed
Titan Destructor Pin

- IASR: 4 Titan Guns Destroyed
Troop Transporter Pin

- IASR: 10 Titan Air Drops
Titan Defender Pin

- IASR: 7 Titan Defend Score
Infiltrator Pin

- IASR: 5 Headshots with Sniper Rifle
Wheels of Hazard Pin

- IASR: 5 Road Kills
Collectors Pin

- IASR: 8 Dog Tags
Explosive Efficiency Pin

- IASR: 8 Kills with Explosives
Emergency Rescue Pin

- IASR: 8 Revives
Tumbler Pin

- IASR: Surviving the Titan Assault
Firearm Efficiency Pin

- IASR: 4 Kills with Handgun
Clear skies Pin

- IASR: 10 Kills with Air Defense
Close Combat Pin

- IASR: 10 Kills with Shotgun