Captain 1st rank (Russian: капитан 1-го ранга, romanized: kapitan 1-go ranga, lit. 'captain of the 1st rank') is a rank used by the Russian Navy and a number of former communist states. The rank is the most senior rank in the staff officers' career group. The rank is equivalent to colonel in armies and air forces. Within NATO forces, the rank is rated as OF-5 and is equivalent to captain in English-speaking navies.[1]