I figured this would be helpful for some of our MD members. Here is the complete checklist straight from the inspection station.
Note that it does require cats to be present and there is a section for "glazing", which is window tint. In this example from last year, I was good to to go with the exception of needing new rear brake pads. It is fairly detailed as far as what must be present and fuctioning, but things don't have to be perfect. My SES light was on during the test for low cat efficiency at the time and it wasn't an issue. The good is news is that once you pass, you don't have to do it ever again as long as you have the car in MD.