> in which case I probably don't know the language, or two because I have made a conscious effort to get an English version of the browser.
...or because your browser defaults to sending en-US even though you're using a Danish-localized browser on a Danish operating system, as described by the parent comment.
I don't think you've read the parent comment very closely, if I'm mistaken please point out to me where they exactly discuss localization of browsers and Danish operating systems? Those are factors you've put into your definition of what by default means.
It is however not what I experience when I look at my Danish localized firefox because it sends da-DK by default, and my english browser sends en-Us, because I took the effort to make it so, because I don't much like the Danish language for UI.
I admit this is just a quick look over of the different language browsers I have on my system. What do the different language browsers on your system do that you feel so confident in telling me to pay more attention to the parent comment?
> many browsers would send "en-US" by default, and so it wasn't a reliable indication of the user's actual language
Indicating that "the user's actual language" and "en-US" are different. Yes, I extrapolated this to both the browser and the operating system having a different language, maybe it was just one or the other.
> What do the different language browsers on your system
From the parent comment:
> Google has been doing this for almost 20 years. [...] The rationale (which I still don't agree with) was [...]
I don't have any 20 years old browsers to test with, I'm afraid.
If someone has been doing something for 20 years the normal interpretation of that would be they started doing it 20 years ago and are still doing it, and you probably don't need 20 year old browsers to actually test it.
...or because your browser defaults to sending en-US even though you're using a Danish-localized browser on a Danish operating system, as described by the parent comment.