Dirndl Right!

Do you know your panne velvet from your coupe de velours? A raglan from a dolman, a dirndl from a full circle? Can you tell Louis Armstrong's trumpet from Karl Lagerfeld's?

The recent fall collections were the best in years, relying on familiar and untricky shapes, often in luxury fabrics. Some of the fabrics and silhouettes haven't been around in years, so it's time for a refresher course:

*Panne velvet: Shiny velvet with pressed pile, used best by Geoffrey Beene and Ralph Lauren.

*Coupe de velour: Cut velvet, with pattern in velvet pile on a sheer ground, used effectively by Oscar de la Renta and Bill Blass.

*Dolman sleeve: Sleeve with a deep armhole that tapers toward the wrist, used well in coats by Geoffrey Beene and Calvin Klein.

*Raglan sleeve: Sleeve set in by seams extending to the neckline, less popular with top designers this season.

*Dirndl: Full skirt gathered at the waistband, the choice of Calvin Klein for his longest skirts.

*Full circle skirt: Made from a circle of fabric, giving a small waistline and a wide hem, used well by Donna Karan, Ralph Lauren, Oscar de la Renta and Anne Klein.

*Trumpet: Slim skirt that flares at the hem with gores, godets, pleats or bias cuts, used by Karl Lagerfeld and Bill Blass. An Attack of Vintage Black

"Dressing up for the concert? Not at all. This is the way I dress all the time," said Lisa Lin, who was wearing black velvet and lace to the Siouxsie and the Banshees concert at the Warner Theatre Monday night.

It was a young and dressy crowd, wearing clothes anchored in punk but with flashes of romantic detail. Most of the clothes were black, and the elements of brocade, satin, leopard print and lace were clearlyil, finds from vintage stores. "I'm all vintage," said Michelle Hammond, a hairdresser at Harlow Hair, dressed extravagantly in belted black lace and pleated chiffon skirt. "I dress this way all the time."

Her chum Erica Hoffman, a student at James Madison High School who was wearing spider-web gloves with her blackxl outfit, agreed. "Yes, I dress like this for school," she insisted.

While there were some spurts of color and some jeans and jams, the predominant scheme was black -- black clothes, black shoes, black hair. "This is the way I feel so this is the way I dress," said Joe Smith, an actor, who was wearing almost total black with a straw hat and John Lennon glasses. Christopher Gott, a student at Old Dominion University, wore a long frock coat he said was a discard from his church, several crosses and boots with chains. His friend Mitchell DuRette, a student at Christopher Newport College in Newport News, was also in black, but swathed in a huge white cotton shawl on which he had painted the face of Siouxsie. "I always wear black because, well, I always wear black," he said.

Stephanie Voss, a student at the University of Cincinnati, was one of many wearing a hat over long wavy hair. Hers, like others, was a Jackie O pillbox that topped off an eclectic vintage look ranging from the 1940s to 1960s -- including what she called a "tacky pleather" car coat, belted tunic and flowered leggings. University of Maryland student Maria Balestri's get-up -- a black leather jacket over an old long faille coat and red crinoline -- was topped with a fancy brimmed hat. "For this occasion I wore my 1900s look," she said.

That's as good a description as any. Givenchy for the Duchess

The Duchess of Windsor, always so precise and caring about the way she looked, was buried in an extravagant pale blue satin gown by Hubert de Givenchy.

A share of the vast number of clothes accumulated by the duchess have been returned to the design houses. Her furniture will be given to Versailles and the Louvre. Brooches will be given to the Duchess of Kent and Princess Alexandra, and the rest of her jewelry will be sold to benefit the Pasteur Institute. Another Opening With Facile Fashions

Janet Irwin began focusing on designs for women whose movements are restricted when she was asked to make a dress for someone with arthritis. "It had become too painful for her to put on her regular blouses and dresses, and her daughter had unhappily resorted to dressing her in a bathrobe put on backwards," Irwin says.

More than a year ago, following study with physical and occupational therapists, Irwin and her partner Pattie Taylor developed a line of clothes they call Facile Fashions Inc. Dresses and blouses have openings that fasten with Velcro down the length of the garments. Because of requests, they have recently added wrap skirts, jackets, vests, nightgowns and slips with easy access. A brochure with color photographs of many of their styles is available by writing: Facile Fashions, P.O. Box 10510, Rochester, N.Y. 14610. Fur du Jour & Diana's Dress

Notes de la mode: The surprise hit of Expo 86, the 1986 World Exposition in Vancouver? The three-times-daily fur fashion show in the Russian pavilion . . .

Also noteworthy -- Diana,xr the princess of Wales, in the loosest-fitting dress we've seen her in to date. Is the sapphire headband, made from a wristwatch contrived as a distraction from a possibly pregnant figure? Irish Eyelet Styling

Irish designer Pat Crowley took to the road five years back when the recession got so bad in Ireland, "I would have had to close my workroom, putting 14 women on the dole queue." The political situation in Ireland continued to keep tourists away, she says. Her traveling and selling in Europe and the United States to women such as Marylou Whitney and Ethel Kennedy has kept business flourishing.

Crowley was back in Washington Wednesday with her collection, modeled at the Irish Embassy. She uses the best of Irish linens and laces in nontraditional ways, and uses Irish tweed equally unexpectedly, often beaded and mixed with silk and satin and velvet. A large part of the collection is in silk and taffeta, for evening. Oh! de Cologne: Perry Ellis' R-Rated Ad

What are you missing if the publication you read has refused to carry the new Perry Ellis men's fragrance ad? Not a lot. The fuss is over the suggestion of a four-letter profanity in an ad that otherwise would rate no special attention. And probably won't sell much perfume.

On the right-hand page of the two-page ad is a bare-chested male model, Matt Norklun, lounging awkwardly in a chair. On the left, above a picture of the bottle, are eight paragraphs of self-obsessed copy such as: "I know I'm very good-looking and there are days when that is enough. Some nights, when I'm alone, it's not." Among those that passed up the ad because of the implied expletive: The New York Times Magazine, and all Fairchild publications -- most noticeably Women's Wear Daily.

The ad was created by the Della Femina, Travisano & Partners.