What goes on a pit beef?

Alright context here: I've lived in Baltimore for 27 years and in my time I've had quite a few pit beefs. Since I was a kid, I've always put horseradish or tiger sauce (horseradish mayo) and shaved onions on a pit beef, and with the exception of the occasional barbecue sauce user I've never seen anyone put anything else on one. So I'm at the Ravens game tonight and they have this Poe's Pit shop that's selling pit beef, so I go over to give it a try. The beef itself is pretty solid, but when I asked for horseradish they put some yellowish sauce that tasted like remoulade on it. This begs the question: are there people out there putting remoulade on a pit beef? Is this a thing or is it the stadium being weird again?