Pewt describes non-binary people who present in a gender neutral/androgynous way. They do not necessarily have to identify as stellarian, abinary, androgyne, or a similar neutral or androgynous gender.
Pewt is a term from the pallet system of non-binary gender presentation. It's used to describe non-binary people's gender presentation without having to use the binary language like "masculine" or "woman-aligned". It is similar to the lesbian terms "butch" and "femme". The term was designed to be used along side the galactian alignment system, but can be used by any non-binary person. For example a androgynous presenting, masculine aligned non-binary person could call themself pewt solarian.
The flag was designed by Tumblr user Elfiot, the coiner of the term. The flag has a combination of the alchemical symbols for air and earth in the center.
Pewt is derived from the word "pewter," which is a shade of grey.