I don't recall browsers behaving all that differently in the 1990s. Per W3, re MSIE 4.0, in 1997: > The Accept-Language header defaults to the current System U

I don't recall browsers behaving all that differently in the 1990s. Per W3, re MSIE 4.0, in 1997: > The Accept-Language header defaults to the current System User Locale ID but can be overridden by user.