/melee aggro=1 will attack the mob from however you approach it, and will not change upon mob turning,
/melee aggro=0 will disable taunting, and will sircle you behind the mob as the mob turns, it makes it very obvious you are using as you always turn and strafe and move with the mob, as if you were being pathed by EQ itself.
So,
/melee aggro=1 will keep you where ay put yourself on the mob.
If you want to see where all your melee commands are currently set, and what options you have, just type
/melee. this will make you a list of all the current melee settings for that character, it's always a good idea to check because certain classes seem to have different defaults.
Also remember, anytime you chaneg any of these, you must do
/melee save, or the next time you log in, they will all revert back. Looking at this list is also a good idea as it allows you to control what abilities you want to use, ei if you want to bash instead of kicking, you may want to turn kick off, otherwise, wherever it is at in the chain it will perform that task without regard to it locking out another ability such as disarm, taunt, bash, slam, kick, flying kick, dragon punch, round kick etc. If they are all turned on ya get a nice mix, but monks for example seem to do the most dmg with flying kick, hence why would you want the chance of it performing dragon punch, or round kick instead, let Master Wu's AA perform those for ya =)