Iv been looking at all my southern lord Cd's, and I noticed something, a a lot of them have a label on the side or on the bottom that say "Sunn 84" or something like that, I know sunn O))) is one of the most notable band's in the label, and they sit in on a lot of recordings with boris and other bands, but does the tag mean anything?

That's just Southern Lord's label code, dude, sort of like how Relapse Records' is RR, Regain Records' is REG and Candlelight Records' is CDL. The number you see after "SUNN" tells you how many albums that the label has released at the time of the album's release (so "SUNN 84" would be the 84th album Southern Lord released). It's quite simple, really.

I looked it up. The founder of Southern Lord is Greg Anderson, also the dude from Sunn O)))

I see, thankyou.