I was poking at the Toughness powers, and tripped across this phrase under Mythic Toughness' musts: You must have a permission that grants this ability.

I've read through the chapter, the index, and done some searching throughout the PDF... I can't find anything else that matches up to this rather particular phrasing, neither in the other Toughness abilities or anything else Mythic.

Is this an artifact from a previous version of the rules text, or am I missing something?