"Chief petty officer" refers to two ranks in the Royal Canadian Navy. A chief petty officer 2nd class (CPO2) (premier maître de deuxième classe or pm2 in French) is equivalent to a master warrant officer in the Army and Air Force, and chief petty officer 1st class (CPO1) (premier maître de première classe or pm1) is equivalent to a chief warrant officer in the Army and Air Force. In spoken references, chief petty officers may be addressed as "chief" but are never addressed as "sir".