Advanced Weapon Training is a program alluded to in the Phazon Mines of Metroid Prime. A computer screen in the Omega Research room mentions that Science Team is now accepting volunteers for it. This may indicate that the weapons in question were experimental and likely sophisticated weapon technologies, as this training is said to have been administered by Science Team and not a military force of the Space Pirates. It is unlikely that Elite, Trooper or Shadow Pirates are the result of Advanced Weapon Training, as candidates for the former two positions are selected by High Command, and Shadow Pirates, which use cloaking technology, engage their foes with melee weapons.
"Science Team is accepting volunteers for Advanced Weapon Training."