arclite
is one Smokin' Farker
Y'all are forgetting the poppy-seed bun!
Poppy seed isn't a requirement, Neither are tomatoes and as discussed, sport peppers are requested.
Mustard, relish, onion, pickle (and to a lesser extent celery salt) are the most universal toppings.
Tomatoes seem to be more prevalent on the northside. On rare occasion you see sauerkraut.
Some stands use poppy seed buns, some don't.
Even an all-beef dog isn't required. It's only been in the last 20 years when Vienna/Dave Berg and Hebrew National became the dominant sausage style did all-beef become a thing. You can still get Leon's, which is a pork/beef dog sometimes referred to as the "gentile dog", at some of the older stands around the city.
Then there is the delicious Superdawg, which is not a Chicago hot dog. It's a Superdawg. And Maxwell Polish...
sorry for the hijack. I really like my Chicago dogs.