Find the entire series on Smashwords.
Now, to the topic at hand. Runes are a written language, but it's kind of like everybody got to make it up partially as the wrote whatever. The alphabet, called Futhark, is a cross between letters and a single graphic standing for an entire word. For example, fehu means cattle, but it can be used in the context "Einar is fehu." which would make fehu mean wealthy. Check out the entire alphabet at the Rune Meanings site.
It appears that the Norse also used various codes. Passing along secret messages about the next raid? But what can you make of the code which reads "Kiss me?" Um, maybe the Norse were just having some fun with language. Oh, those barbarians! Not only could they read and write with runes, they could also add playful coded messages.
I didn't need a coded message to find this fascinating article about Rune codes. I found it in the G+ Vikings Mythology group. Now that I know the base site, I'll get to explore more of the science behind the myths.
Read Mysterious code in Viking runes is cracked on the Nordic Science website.
Can you figure out the jötunvillur code on this piece of wood? Hint: I mentioned the interpretation above.
If you read runes, maybe you can parse the code from this piece written in both runes and code. The author is a bit of a braggart. Since it's a bit difficult to even see the markings, I'll help you out. It says, "These runes were carved by the most rune-literate man west of the sea."