Parents should conduct their arguments in quiet, respectful tones, but in a foreign language. You'd be surprised what an inducement that is to the education of children.
Judith MartinPeople think, mistakenly, that etiquette means you have to suppress your differences. On the contray, etiquette is what enables you to deal with them; it gives you a set of rules.
Judith MartinA wedding invitation is sent by people who have been saying, "Do we have to ask them?" to people whose first response is, "How much do you think we have to spend on them?
Judith MartinEtiquette 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 Martin