Final answer:
FPF stands for Fire Power Factor and Danger Close refers to the minimum safe distance for firing artillery or air support.
Step-by-step explanation:
FPF stands for Fire Power Factor, which is the measure of the effectiveness of a weapon system. It is calculated by multiplying the caliber of the weapon by its rate of fire.
Danger Close refers to the minimum safe distance for firing artillery or air support to avoid hitting friendly troops. It is typically defined as a distance that allows for accurate and effective fire while minimizing the risk of friendly casualties. Both concepts are important in military strategy and operations.