UPC codes: what field type do ppl use?

[crobaseball]

Ok, I'm not sure why I'm having trouble with this, but I've got UPC codes I need to load into my db. I was wanting to do it as a number, but obviously 12 digit numbers are too large for any number field, and frankly, I don't want to take up this much room. Anyone work with these? Do you use text fields? Are UPC's always the same digit length so I won't run into probs with trying to sort/match in the future?

[June7]

UPC is an identifier. Identifiers should be text field.