Inexian

Inexian, or Inexbeing, is an umbrella term for alterhuman experiences in which their identity cannot be described, named, or understood by others.

This does not mean that the identity is unknown; rather, the identity itself is something that can’t be understood or described due to its nature. It's possible that the user understands their identity perfectly well, but it's unable to be described or comprehended by other people.

The term was coined by extranth on Tumblr. It is not exclusive to otherkin; any alterhuman identity may be inexian.

Terminology
There are various examples of inexian identities, including inexkin, which is where someone's kintype is inexian. Furthermore, the prefix for inexian terms is inex-, and may be for any kind of alterhuman experience, including vague or unnamed ones.

Flags and Symbols
On the flag, the black represents the "containment" of understanding being kept to oneself (or having none at all), the pink to dark blue colors reference a lack of clarity, with a sliding scale going from fully clear to completely unable to be identified, which showcases the range in experiences an inexbeing may have. The green showcases one's personal experiences with their alterhuman identity.