The Armanen row is Guido von List's, published in 1908. This character and its inverted partner have a documented later history that has to be stated with them.
The character behind it
Man corresponds to the Younger Futhark character whose Old Norse name was madr, meaning man in the sense of a human being. The rune poems gloss it as the joy of man and the increase of dust, a memento mori, and the Old English tradition reads its equivalent in the same register.
What von List did with it
He kept the M value and the name in German form, and read the character as life and the human being upright. In his system the inverted form of the same character, which he calls Yr, carries the opposite reading.
The afterlife
That upright and inverted pair was taken up in National Socialist Germany as a printed convention: the upright character used to mark a birth date and the inverted one a death date in printed announcements and records of the period. The pairing is von List's and the usage is documented.
The atlas records this because the two characters are still encountered in that role and the history explains why. It is not a claim about the medieval rune, which is attested for centuries before any of it and carries no such convention.
The Armanen row as a whole was taken up in volkisch circles and by National Socialist organisations in the 1930s and 1940s.