Armor Piercing

"Armor Piercing" or "AP" refers to weapons, configurations, or ammunition that is designed to be effective against Vehicles or MAX armor only, usually having little effect on infantry.

For example, white 9mm are Anti-Infantry, while gold 9mm rounds are Armor Piercing. While the latter is effective against enemy MAXes and small vehicles, it will do very little damage to enemy troops.

While AP is more effective than AI against vehicles, the specific Anti-Vehicular weapons class is a better choice for combatting heavy armor.