I never really thought much of this code during my adventures reverse engineering the games. But here are the changes (well, additions to make changes) from H1's toolkit. That second line checks if the scenario (essentially the 'entry point' data for a map) is for the campaign (vs the mainmenu or MP). If it isn't a campaign scenario, none of these changes are made. It changes the "plasma rifle.weapon", "pistol.weapon", and "bullet.projectile" tags.