Etiquette is about all of human social behavior. Behavior is regulated by law when etiquette breaks down or when the stakes are high - violations of life, limb, property and so on. Barring that, etiquette is a little social contract we make that we will restrain some of our more provocative impulses in return for living more or less harmoniously in a community.
Judith Martinit's no longer socially acceptable to make bigoted statements and racist remarks. Some people are having an awful time with that: 'I didn't know anybody would be offended!' Well, where have you been? I remember when people got away with it and they don't anymore. That's fabulous.
Judith Martin