Roman numerals are a numeral system which was used in Ancient Rome. It uses letters instead of numbers to represent values. You may have seen Roman numerals on clocks and on TV or film credits.

The use of Roman Numerals began with the fifth edition ... is technically held “next year” from the regular season, i.e. this year’s Super Bowl, held in 2025, is for the 2024 season.

Some elements, particularly the transition metals, do not always have the same valency in their different compounds. The valency of these elements is usually given in roman numerals inside brackets.