Nearly a month before Brennan Dorn graduated from Georgetown University last year, her parents invited 50 relatives and friends to an elaborate buffet dinner on the big day.
Then they got down to the serious business of planning a feast that both would cook: spicy skewered shrimp, piquant eggplant dip with toasted pita chips, phyllo triangles, vegetable-stuffed flank steak, Tuscan chicken stew with saffron rice. A caterer would provide additional treats and a rich dessert; dishes, flatware and serving pieces would be rented and a fully stocked bar set up.
Only one question loomed large for hosts David Dorn and Diane Daly: How many people would actually be coming to the fete in Dorn's Adams Morgan apartment?
"With just a week to go, I still hadn't heard from 60 percent of my guests -- in town, out of town, kids and adults," says Daly, director of fashion and communication for Hecht's. "The RSVP on the invitation was clear. It was a dinner, so I really needed to know how much food to get, how much wine, how many plates. I got on the phone or e-mailed those people and asked them if they were coming."
Despite her best efforts, Daly didn't reach them all. "Some showed up without responding. I opened the door, they'd be standing there, and of course I said I was thrilled to see them."
Understandably, she was smiling through clenched teeth.
Anyone who has ever organized a social event -- whether dinner at home, a potluck picnic or a large formal wedding -- knows all about the value of RSVP, the French acronym for repondez, s'il vous plait, or, in plain English, please reply.
With school back in session and the holidays fast approaching, the problem of non-responders will only escalate, say the experts.
"We live in a much more informal world today, and that leads to less attention being paid to the proscribed way of doing things," laments Peter Post, fourth-generation etiquette guru whose great-grandmother Emily wrote the first of several guides to proper behavior in 1922. "Another thing, frankly, is the whole new world of technology, which means everything moves much faster, and people will say, 'Well, maybe we'll do it if we have time.' "
In another sign of slipping standards, during the past few decades, many youngsters were not taught how to reply to invitations, and grew into clueless adults.
"The old family structure devolved and changed from the classic 1950s -- Dad at work and Mom at home being constantly on top of things the children were doing -- to a lot of single parents or children of working parents being taken care of by grandparents, just whole new types of people raising kids," says Post, author of "Essential Manners for Men" and a director of the Emily Post Institute in Burlington, Vt. (www.emilypost.com).
Party planner Linda Garner, who runs Gala Events in Bethesda, puts it more baldly: "People are rude," she declares. "We are getting more and more lazy. You know that the correct way is for people to write a note saying they will or will not attend. It's very difficult because people don't know proper etiquette, so they will either call you on the telephone or they will do nothing. It's ridiculous. Even with an RSVP card, a stamped self-addressed envelope and 'RSVP by a certain date,' they don't."
Honore McDonough Ervin, co-author of "Things You Need to Be Told: A Handbook for Polite Behavior in a Tacky, Rude World," considers an RSVP more than a simple nicety.
"It is a direct order," she says, invoking a phrase from her girlhood as a Navy brat.