The abbreviation appears at the bottom of invitation cards, often followed by a deadline and a contact. It commits you to reply either way: you confirm your attendance or you decline, but you never leave a card unanswered. The rule is set down by Debrett's: every invitation calls for a prompt reply, acceptance or refusal, and going back on your word at the last minute is considered rude. In the world of private parties, the RSVP is no decorative courtesy: it conditions access. At the MY Yacht Monaco party, held aboard a superyacht in Port Hercule during the Monaco Yacht Show, from September 23 to 26, 2026, the invitation comes with a mandatory RSVP to the organizer: you introduce yourself (profile, company, reason for the request), then await validation of the list. That list closes before the show opens, and a late request is no longer processed. Replying early therefore pays twice over: you hold your standing, and you keep your place. Three usages to remember: you reply through the channel indicated on the card and no other; you reply for the people named on the invitation, without bringing anyone else; and an acceptance is a commitment, a last-minute no-show being the most frowned-upon offense.