You exclude from base weight the consumables--water, fuel, food--whose weight varies with the length of the trip. However, I notice that most published gear lists, especially those at the UL end of the spectrum, omit a camera, even when they publish pictures of their trip! There is also the issue of a few other items whose weight varies according to the length of the trip (which base weight does not). In my case it's some extra toiletries that I require for medical reasons, which add up to almost a pound and a half on a 10-day trip. I suppose one could also include in consumables items like sunscreen and bug repellent, where you also take more for a longer trip, but that's getting, IMHO, a bit nit-picky. I don't think anyone empties out a dropper bottle containing several days worth of sunscreen for an overnighter.

Anyway, the theory is that base weight remains fixed regardless of the length of trip, while consumables vary. Therefore only the base weight is comparable to others because it is the same regardless of how many days you go out. As an ex-accountant, I prefer to call them "fixed weight" and "variable weight."

My base weight, without camera (to be comparable to the UL folks), is 10.7 pounds. This is for trips at high altitude in the northern Rockies, when it often freezes at night and can snow in July and August. I would take a little less for the Cascades in the height of summer, but probably no more than half a pound . Add in camera (with extra batteries) and fishing gear, and I'm up to 12.1 pounds.