The initials R. S. V. P. stand for a French phrase, “répondez s'il vous plaît” which means “respond, if you please” or “please respond.” It is usually found at the end of a formal invitation, asking the recipient to let the sender know whether or not they will be accepting the invitation.

When members of the aristocracy wanted to throw a party, invitations had to be hand written. Soon this practice became an art form, with fancy lettering (calligraphy) and decorated parchment paper. The paper would be folded to keep it from getting dirty and placed inside an envelope with the invited guest’s name and address on it. It was sealed with wax with the family crest. Delivery would have been on horseback, possibly on muddy roads, so the envelope protected the inner invitation.
After the printing press was invented, invitations could be printed instead of hand written, and a piece of tissue paper was inserted inside the invitation to keep it from smudging. No longer needed today, the tradition is still upheld. The custom of having two envelopes comes from those early aristocratic days as well. People’s residences didn’t have addresses on them, so the instructions given were sometimes very long. So, the inner envelope held the actual invitation and the outer one was for directions.
So how did French initials wind up on invitations of today? The French were very etiquette conscious, as were many in civilized society. The Italian diplomat, Conte Baldassare Castiglione, wrote the first etiquette book in the 16th century. It was a book concerning proper behavior among the nobility of that time.
However, most of Western etiquette comes from the French, especially the court of King Louis XIV. On his palace in Versailles, he had the rules of proper behavior written on “tickets” or “etiquette.” These were either posted, like signs, or were the actual invitation to an event with the rules written on the back. In the United States during the 19th century, French was the chosen language of high society and refinement. Some say that the RSVP is just a polite reminder of something that the recipient should already know; that it is proper etiquette to let your host know whether or not you will be attending. In other words, if you receive an invitation, you should reply.
Here are the steps showing how to write and send an invitation.
These initials, R. S. V. P., also stand for a few other things:
However, most of the time, RSVP refers to the simple reminder to please let your host know if you plan to attend their gathering.