Yeah, so HAI groups rooms into units of 8 or 16 (some panels are different, and I can't remember which it is off the top of my head). That's what the 1-1, 1-2, etc are. Room 1, Unit 1. When it goes to 2-1, that's Room 2, Unit 1.
You can have blank lines in the units setup, you don't have to...