OSLO, NORWAY—Runologist K. Jonas Nordby of the University of Oslo has deciphered the ancient Norse jötunvillur code, found on nine known inscriptions. Nordby used a thirteenth-century stick on which two men had carved their names, Sigurd and Lavrans, in standard runes and in the code. The confusing system requires that the reader have a good working knowledge of the runes in order to swap them out with others for sounds in their names. “What if codes were used like a game, playing with a system? With jötunvillur, you had to learn the names of runes, so I think codes were used in teaching, in learning to write and read runes,” he told The Guardian.