Yea, I see that mark crop up in a lot of various RPGs. Earliest I can recall is one of the dungeouns in the original Legend of Zelda is that mark.
It's that idiot Hitler's fault that it's become the bad sign it is today. ...well, as stated, he rotated and flipped it, of course.
Currently I'm main-ing two full-time fisher-girls. They fish. A lot.