To be classified: DIFFICULTY_SCALE
I discovered this when looking in My Documents for my latest screenshots:
It seems if you look in the my games folder of my documents, you will find a folder called 'Freelancer'. I went inside and found an ini called PerfOptions. I opened that and found a DIFFICULTY_SCALE setting. I soon discovered that setting it higher made for a more challenging game, and vice versa. Also, I discovered that setting it to zero just makes you invulnerable. Quite a great discovery, eh?
Just telling you.