No true Scotsman

• Wikipedia: No true Scotsman

• No Proper Statesman

Opposite fallacy

• hasty generalization

• dicto simpliciter ad dictum secundum quid [1]

• Wikipedia: Accident (fallacy)

• Wikipedia: Secundum quid

• It’s actually the same fallacy, because ‘no true x does y’ is the same as saying ‘all true x does not-y’. [2]