What is a Maryland style deli?

We went to the Charcoal Deli for the first time yesterday. The only thing that seemed to distinguish this place from any other style of deli was that they put Old Bay on their french fries. The specialty sandwiches didn't look that appealing (Italian sausage or Wisconsin brat? Is Maryland the National Geographic Bee state?). However, the 2 sandwiches we got (roast beef and turkey) were awesome. Maybe a Maryland deli is place that makes good sandwiches w/o gimmicks.