Question for those philosophy majors out there... I'm having trouble with the general concept of labeling something "ethical", as thought it were a binary qual

Question for those philosophy majors out there... I'm having trouble with the general concept of labeling something "ethical", as thought it were a binary quality akin to "kosher". My understanding is that "ethics" classically refers to any particular set of moral principles. That would include Mahatma Gandhi's, Adolf Hitler's, and Jeff Bezos'. So I'm assuming that usages such as "ethical game development" imply adherence to some particular, unstated ethic. But I'm not clear what ethic they're implying.