I've seen this sticker, next to the '7th' in the highway sign, for the past couple of years. I've seen it in the strangest of places, including this sign, but mainly on cars. I for the life of me, do not know what it is a symbol for. For as many times as I've seen this symbol around town, it has to be very popular whatever it is and I'm not in the right age category to know why it is popular. Can you clear up the mystery on what it is?