In Kryptos, does the fourth part allow the use of Roman numerals?

It allows them, yes, but to no effective purpose that I can see.

K4 Roman Numerals

This was a little random but not entirely unbelievable.  It makes me curious about how similar notations/systems could be incorporated into K4.  I’ve considered foreign languages before but it seems there are quite a few linguistic tricks besides that could have been employed in K4.  Not all of them would mean anything and I’d never say I knew what they all were but it leaves an intriguing door open for further efforts.

Kryptos remains undefeated.