Great guide to EQ2 macros Khatovar - thankyou!

If I may, I'd like to add a little more to this statement:
You can either fill in a player's name so it will cast on that target no matter what you target, or you can leave it blank to make it cast on your current target.
- leaving the player's name area of the macro blank can also cause the beneficial spell to be cast on your current target's implied target assuming the current target is a mob. For example, you are attacking a mob who is currently attacking another group member. You can cast a heal and it will fall on the attacked group member without having to explicitly target them.

Some listings of ingame 'slash commands' which can be used in macros can be found at these links (some are getting pretty old now and haven't been updated for a while):
http://www.tentonhammer.com/node/54475
http://eq2.wikia.com/wiki/Slash_Commands
http://eq2.allakhazam.com/wiki/slash_commands_(eq2)
http://www.eq2interface.com/forums/showthread.php?t=982