The Toggleable Ammo Switch between Ammo Types is not a form of ability, it seems...

A gun could be assigned several projectiles in gun_to_projectile table, and in extension, the ships that carries them...An Artillery unit could shoot shots, canisters, shells; Ships guns shoots chainshots and grapeshots this way, right?

My Question is, How the game "Knows" that the projectiles assigned in the gun_to_projectile tables are different kinds, different class of projectile - assigning a projectile of a particular class makes the icon for the projectiles appears in the UI - what governs this? is there a table?

How does it works? How The Game "Knows" that a particular projectile is the basic default projectile and the others are the alternative? How about the path?