I only just learned this today myself. We're more than twenty sessions into the campaign and I've been trying to find some way to have the characters learn how to interpret the carvings in Omu.

I'd considered using Orvex or the Tablet, but one of my players will really enjoy deciphering the carvings by piecing things together over time. This had been a super daunting task for me, because I thought Old Omuan was a language.

TIL: Old Omuan is just a script. I'd already read the section on the Queen's Decree and the sidebar texts. I'd completely overlooked multiple mentions that it is just a cuneiform script for the common language. Maybe you did too. If so, I hope this helps you.

Now, I'm looking for a font that can handle Old Persian Cuneiform. If I find it, I'll drop an update here. If anyone else finds any, maybe this would be a good place to comment them! I'd love to hear how people have designed handouts for their players using some form of cuneiform script for this portion of the campaign.