Can't we just use SI prefixes or spell the numbers out instead of using some random alternate convention?
Using Roman numerals for anything is a waste of everyone's time.
No one would be so asinine to mix numeral systems. Same thing with percent, which originally was rendered as "per-cent", as in "per hundred".
HN is the only place I see this notation used.
The great thing about standards is there are so many to choose from.