I found this in the FS2 Wiki:
"The heavy photon beam cannons now mounted on all Terran warships were initially reverse-engineered from the superweapons mounted on the Lucifer in 2335 by the GTI engineers working on Project Hades. The ill-fated rebellion of these engineers the next year in their bid to overthrow the GTA led to the classification of the weaponry for several years. Once functional beam weaponry was proven to be practical, reliable, and superbly useful, a Vasudan variant was developed for deployment on the Sobek class of corvettes. These 'slash' beams maximized the spread of the beam fire on a wide arc across the target's hull, increasing the chances of disabling subsystems and turrets. Both Slash beams and Line-of-Sight (LOS) beams are now standard on all Terran warships."
Beam types??? since when there are Beam types beyond the AAA beams and the anti-warship beams....
I really don't know where the hell did they get that...