That's just dps being dumb, not some secret marking system.
I only ever mark skull and very rarely x, I just mark a new skull when the original is dead.
This. Skull is the one that everyone kind of understands, because it's directly symbolic. Anything beyond that and you shouldn't be surprised if someone in the group doesn't magically know it.
Devolore
This. Skull is the one that everyone kind of understands, because it's directly symbolic. Anything beyond that and you shouldn't be surprised if someone in the group doesn't magically know it.