if it doesn't meet the unwritten criteria, its not tr00, and since that criteria is unwritten, you can call everyone untr00 for whatever reason that doesn't exist.
Yeah what the others said, it's about the vocals, the scratchy guitar sound, fast riffing if you're tr00, lyrics can be pretty much about anything although anti-religious is the norm.
Without the lyric sheet you'd never be able to tell what they're screaming about. It could be the hypocrisy of Christianity or taking a dump and then noticing you have no toilet paper! AAAAARRRRRGGGGHHH!!!!!!!!