Incomprehensibilization of the categorization
Making the categorization hard to comprehend. The lines of who is or isn't included and on what basis people are included or not bay be fuzzy, mystic, self-referring, or simply undefined. Either way, it may be taboo to discuss – complete with a whiff of conspirationalism and guilt by association: “If you question the concept of this category of people, it's probably because you are secretly one of them”.
This is an abstraction of categorism.