The answer is all of them. The code certainly isn't finished, but the bones of all the needed stuff is there. The code checks whether there is an item where you are trying to equip something (and un-equips that if needed) and then equips what you've selected. There's also checks in place to make sure your character CAN actually use it, though I need to flesh those out further. I also wrote the basics of the code that will then update your character with any new stats from whatever it is you equipped, so a better armor score, or new attack profile and such.
I should be able to extend this out to all the other equipment slots easily enough, then just flesh out the details around stat updates and the like. Oh, and I need to update the code when the characters are loaded from the server to actually equip all the items properly now that this functionality exists.