"Parts of Japan gave criminals tattoos on their arms. Many are simple lines around the arm. On the bottom line, the third left, I can see the sign of “悪”, bad in Japanese. This was Kishu´s (紀州/now Mie and Wakayama prefecture) tattoo.
the valknut- vikings painted this on their shields to call the Valkyrie to take them to Valhalla if they were killed, Jake had this tattooed on his forearm in honor if his viking decent/roots. Along with some ancient runes.