Although I agree that English/Imperial Units are still the primary units of commerce in the US, I think the use of the word "official" is technically inaccurate. The US was one of the original signatories of the SI treaty and SI has been a legal system in the US for over a hundred years. —Preceding unsigned comment added by Paolorausch (talk • contribs) 12:32, 16 March 2009 (UTC)