"Répondez s'il vous plaît", a French phrase that translates to "please respond" or "respond if you'd please" and word for word means "respond if it pleases you". It is with this meaning that invitation cards and similar documents are often marked with "RSVP." In Western and European culture, it is often considered rude to not reply to an RSVP request whether confirming attendance or declining. Do you got it?

[via]