It does appear, if the citation of IPUMS at the bottom (a cool source of data, for those who haven't seen it: https://usa.ipums.org/usa/ https://usa.ipums.org/u

It does appear, if the citation of IPUMS at the bottom (a cool source of data, for those who haven't seen it: https://usa.ipums.org/usa/ https://usa.ipums.org/usa/ ) means anything, that they are at least using standard classifications. That doesn't mean their distinctions make sense, but at least they're openly available and documented.