RickH
2
You could do this with custom product tags so everytime you setup a new item you select the tax code letter from a drop down box
For all current items you would have to manually go back to each one and assign the code
You could then print that tag on the receipt as you need
Have a search for custom product tags
This is one way i know of there may be other ways, hooe that helps 
EDIT heres the link