The codes.
You can make as many copies of anything in your
inventory as you want, here's how:
To duplicate you need to choose an object that you want to be
replaced with the object you are copying (I suggest using one gold
piece - so that you don't waste anything).
Choose which object you want to duplicate, and drop it on the ground
(be sure to drop it in a clear place - without trees, or cluttered
with other objects).
Then walk about 4-5 inches away from it. And close your inventory
[if you ever had it open to begin with].
Click on the object to walk towards it, and as you are walking,
press the "i" hotkey to open your inventory (while you are walking
towards the object you want to duplicate). Now the hard part, right
as you pick up the object [you inventory is still open by the way]
click on the object that you chose to be replaced. The item will
appear as the item you just picked up, as soon as you drop it back
in your inventory (or on the ground). Remember: Click on the object
in your inventory that you chose to be replaced at the same time as
you are picking up the item you are trying to duplicate.