Mannaz is the letter M
Anglo-Saxon Rune Poem (from ragweedforge.com)
The joyous man is dear to his kinsmen;
yet every man is doomed to fail his fellow,since the Lord by his decree will commit the vile carrion to the earth
Mannaz means man. While it might seem to refer to the male human, in Old English, This particular word is actually gender neutral in its usage, so it does also refer to humanity
Mannaz reversed indicates a lack of the qualities of humanity is present. As some view Mannaz metaphysically as being the Mind, and also the “Higher Self” it can also indicate those qualities being absent or unexpressed as well. I received a particular feeling from this rune today that it is more about the Community and Unity of Humanity, and a the lack of it. As I work in customer service, well lets just say today is going to be an interesting day.