A fork of Rural Dictionary
Observing which toppings another person puts on a hotdog, in order to discover that person's geographic origins. Can also be used to determine that person's level of taste, culture, and culinary refinement. Results of such a test can be skewed if the person being observed puts enough toppings on their hotdog that a hotdog cornucopia results.
I can tell Dan doesn't hail from Chicago. I did a hotdog geography test while we were out, and I noticed he ordered his with ketchup on it.