[Karellen]

> Explaining the argument one more time is not really convincing.

Sorry, I wasn't explaining again because I thought you weren't convinced of my point. Based on your previous reply, I thought you hadn't understood my point. Because if you had, the "well, a millilitre of other liquids doesn't weigh the same either" seems like a complete non-sequitur. I couldn't figure out what point you would be trying to make with that comment if you had understood me. (Knowing that you did, I'm still not sure? Like... so what?)

[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.