Image: On this stick from the 1200s found in Bergen, two men named Sigurd and Lavran have written their names both in code and with regular runes. This helped runologist Jonas Nordby to solve the Jötunvillur code.
Jötunvillur code is to replace the runic character with the last sound of the runic name. For example, the u-rune “urr” becomes r. The problem is that several runic characters have names that end with the same sound. This makes it difficult to know which character the code is referring to.