It's not my place to share Moose's excellent writeup, I'll leave that for him, but I did think it important to share a little goodie I found at my local library. Major Heavensward spoilers ahead:


We can, indeed, close the book on the meaning of this symbol: Archon of Sharlayan. Not that there were many doubts left.

Which leaves that other mark still totally unexplained. I still don't really buy the "Brand of the Scions" explanation, not only because of that guy I never shut up about, but also because neither Minfilia nor Urianger wear it. But that doesn't make it meaningless, either, because...


Whatever it means, we do know it remains an important symbol to Y'shola, so we can assume it still has some important meaning left to be revealed.