Neither describes a experience by those who refuse to define themselves under one gender term. It is not necessarily agender, gendervoid, neutrois, or abinary. One may or may not have a gender. It is an example of an unlabel.
History and Flag
Neither was first defined as it is now and a flag was created for it by Tumblr user beyond-mogai-pride-flags on June 26, 2018.[1]
In the upper left-hand corner of the flag is a Mars symbol and a Venus symbol overlapping. Where they overlap has an X drawn through it. The both and none flags have a similar design.