User blog comment:ChishioKunrin/Taiyang got a tattoo/@comment-26397825-20151027114325/@comment-4010415-20151028223441

I think Raven's symbol is a flipped version of Qrow's. The symbol Yang draw on the chalk board was a flipped version of the one that appeared behind Qrow in the flashback, and the story was about how searching for her mother almost got her and Ruby killed, not about Qrow.

Furthermore, the symbol looks like an eye. If Qrow and Raven are twins, it'd be cool if their symbols are just flipped versions of each other, making up a pair of eyes.