A person who is being prejudice or discriminatory towards someone for their position.
Often used for when a person (cis-man) is being prejudice towards a gay man for doing something typically associated with one stereotype of gay.
Example:
Man wearing a dress: “I’m a top.”
Positionist man: “You are not a top. Tops don’t wear dresses.”
Example:
Positionist man: “I’m masc man, looking for same. No nail polish wearing femmes bother!”