The eighteen Armanen runes were published by the Austrian occultist Guido von List in Das Geheimnis der Runen in 1908. They are his construction, not a historical alphabet, and the useful question about any one of them is what he took and what he changed.
The character behind it
Fa corresponds to the Younger Futhark character whose historical name was fé, meaning livestock and, by extension, movable wealth. That character is genuinely attested: it appears on Viking-age inscriptions and in the medieval rune poems, where the verse on fé is about wealth and the trouble it causes between kinsmen.
What von List did with it
He kept the sound value F and the shape, retitled the character Fa, and attached to it a meaning of his own devising within his eighteen-rune system. Sixteen of his eighteen correspond in this way to the Younger Futhark row; the remaining two, Eh and Gibor, have no counterpart there. His sequence is also not identical to the Younger Futhark order at every point.
What the row is and is not
Von List presented the eighteen as an ancient Germanic priestly alphabet recovered rather than invented, and framed the number eighteen on the eighteen rune-charms of the Havamal. Historians of the subject do not accept the recovery claim. The row was subsequently taken up in volkisch circles and, in the 1930s and 1940s, by National Socialist organisations. That reception is documented, it is a real part of the object's history, and this atlas records it rather than omitting it.