Daft question

What is the indicated fuel tank fill level on an NC30?

Is it the 5mm thick arced tab, aligned to the front, visible through the filler, while the bike is vertical?

On my RVF i tend to fill up to the collar on the inside and a little bit over..just ride the bike for a little bit so it doesn't come out around the cap.

I do this on the side stand, reason being for a bit over the collar is so that when you straight on the bike its level..

OK thanks

Reason I ask is that I'm trying to work out fuel consumption

And short of draining the tank and adding exactly 15 litres I'm trying to know where "top" is

I'll go from the collar