[klodolph]

I guess my response is also "so what?"

If you measure a liquid other than water, then a fluid ounce does not weigh an ounce... so what?

Even water, the density is 1.0 oz/fl oz, but that's as many significant figures as you get. You would often want more significant figures, even in non-scientific contexts.

[Karellen]

> If you measure a liquid other than water, then a fluid ounce does not weigh an ounce... so what?

So that makes "fluid ounce" a bad name. Because it doesn't measure ounces of fluid.

[klodolph]

Ok, I had assumed you knew what fluid ounces were. Yeah, that assumption doesn’t make sense since it’s not used outside the US and a couple other countries.

A fluid ounce is 29.5735 mL.

The “fluid ounce”, being a measure of volume, can be used to measure fluids.