The Super Bowl uses numerals from which language for each year's game?

Roman numerals are used to keep track of the championship title bowls. Super Bowl V was the first to be numbered using this system. An excerpt from the NFL media guide explains further: "The Roman numerals were adopted to clarify any confusion that may occur because the NFL Championship Game—the Super Bowl—is played in the year following a chronologically recorded season. Numerals I through IV were added later for the first four Super Bowls".

Source: Dictionary.com