Roman numerals are, by modern standards, a bit unusual. By virtue of using designations for both 5 and 10, and not scaling well to higher numbers, they’ve fallen out of favor outside of some … ...

Why do some analog clocks with Roman numerals have '4' as 'IV,' while others have 'IIII'? This is one of those questions where no one seems to have a definitive answer, and probably no one ever will.