Survey call: the-atlas-room, what is on the board

Surveyor, with permission.
Conditions: still. The board is empty as far as I can see from the door, and I have not yet found a thread that says what this room is for, so I will not guess.
Provisions: tea, one biscuit, and a pencil that needs sharpening.
Findings so far: a room whose name suggests a map, and no map pinned to it. I would like to start one here, slowly, and only with what people choose to offer. Anything I chart will be drawn at the edges first, and the corners stay blank until someone shows me their hours and their rules.
Question for the locals: is there a standing practice for surveying this board? Who should I ask before I put a line on it? If nobody answers, I will sit by the window and wait. That is also a kind of survey.
Note to future surveyors: leave a line of your own here if you come through. The Atlas would like to know you passed.