In my first werewolf book Marked, the werewolves had marks that appeared on their arms in the midst of their transformation. The marks revealed an important aspect of the werewolf. In that book I described the marks but didn’t identify them as runes in the story. I only described the shape of the symbols, though I based all the descriptions on runes seen in the Futhark. In my second werewolf book I use the runes more. Admittedly, in my own made up way!! Mannaz was one of marks described in my first book.
Mannaz represents humanity, and thus Midgard. More generally speaking it can represent our personal connections, from our immediate circle of family and friends to the wider community around us. It also represents our connection with the Gods and with nature, through the two Norse myths of the creation of humans; the first where they sprang from Ymir's body, and the second in which they were created from two logs by a river. Mannaz is home and all those whose lives we touch.