So, this is the most lamest rule of food I have ever come across and I will, at any chance, do it just to piss people off.
There are soem theories as to why this is the lamest...
1) All the vegetables and ish are already on there (tomato) so you don't need Ketchup [catsup] on your gross hot dog, you fat fuck.
2) Everybody kept taking all the Ketchup [catsup] packets, places were losing money, so they started charging for the packets anywhere from 25¢ to 50¢ per packet so then people just started eating the gross hot dogs w/o Ketchup [catsup].
3) It's okay for kids to put it on their hot dogs up until the age of 10.
Lameness all around, It's a fucking Hot Dog, eat it however the fuck you want. Raw, Uncooked, w/Tabasco, w/Cool Whip®, Dipped in a Milk Shake, Ketchup & Relish, Shrek's green Ketchup and Easy Cheese, or even Slathered in Bacon Grease & Brown Sugar.
It's food, there are no rules.