I tried mapping countries. I wanted all countries to map except the U.S., which I wanted blank. It took a long time to type every country's two letter code. It would have been a snap if all the country codes could be auto-filled and then I could just delete the U.S. entry.
Guest
This functionality already exists. When mapping Country, the Export Values already auto-fill in the two-letter country code. So to achieve the mapping you suggested, you would just have to delete/empty out the field value for U.S.
I think the real problem is that one cannot leave US blank - you can do a space, but there is no way to export blank data for the field. As the admin response says, to delete/empty out the field value for U.S. would result in the value of US being exported, which seems to be the opposite of the desire of the person who created the ticket.