questions about tailgating tent rules

so yeah, i got one for christmas and saturday will be my first game in the burg this year. i thought there was a rule that they could only be set up in grassy areas so people didnt take up parking spots (yeah weaver!) and that was first come first serve. i was looking around on hokiesports and all it said was your tailgate couldnt extend beyond the parking space and block traffic.

so does anyone know the deal? can i just set up in a spot or do i have to get there early and get a grassy spot? i'm really just worried about because the chance of rain and dont wanna have to pregame in the hotel room.