theworldofdreams.com

I looked in the manual and there was nothing there.
What dose it do when you click the boton next to necromancy under your skills.
All it says is "you conect to the netherworld"
<Gaia>

It means that when another player is dead, instead of seeing OOoOOoo oooOOOOO, you see what they are actually saying. Also when you do that next to a grave,you can pull up some undead NPC monster that either gives you necro regs and a scroll or attacks you which you then kill for loot.

It only does those things, however, if your necro skill is high enough.