It’s common knowledge in the West how Roman numerals work.  Some Roman numerals get more use than others.  Smaller numerals, like I, V and X (meaning 1, 5 and 10) get the most use, while the higher ones like L, C, D and M (meaning 50, 100, 500 and 1,000) aren’t as common.  They’re more often found in official use.  Movie credits often give the date in Roman numerals, maybe because MMXVII looks more impressive than 2017 (or, more to the point, MCMLXXXIX looks more impressive than 1989).  The date of the founding of the United States appears on the Great Seal as MDCCLXXVI (have a look at the base of the pyramid on a $1, if you want to see), and writing it that way does seem a lot grander, a lot more appropriate for the founding of a nation than the simpler (and clearer) 1776.  Even the Super Bowl gets a Roman numeral for its title.  (In 2016, what might have been Super Bowl L was marketed as Super Bowl 50, since the NFL had difficulty designing a logo f...