According to Wiki …
RSVP is a process for a response from the invited person or people. It is an initialism derived from the French phrase Répondez s’il vous plaît meaning “Please respond”. The initialism “RSVP” or the phrase “Répondez s’il vous plaît” are still used in current French to require confirmation of an invitation.
As far as I’m aware these simple letters and their meaning have been around forever or at least all my lifetime. It would seem though people are unaware of what you’re asking when this is attached to a formal invitation it can make catering a little hard. Surely even a text is not so hard to send.
My question would be how far do you go to get your answer or like us take no reply as a no show to the event.
My youngest now Mr 23 is getting married this weekend we’re excited, they’re off on their honeymoon to NZ on Wednesday.