IN CASE YOU are not convinced that the restaurant business is volatile, here's a clincher. A few weeks ago a friend came into work saddened because one of his favorite restaurants had disappeared overnight. Cafe Marie in Alexandria had changed its name to Cafe Bernie. And Bernie said he didn't know where Marie had gone.

I said I'd check it out and try to track her down, and I filed the information away for a future column. A few weeks later when I called, I asked the man who answered whether it was Cafe Bernie.

"It used to be, but it's not anymore," he said. It is soon to reopen as the Continental Cafe. So now I've lost track of Bernie as well as Marie.

RESTAURANTS often send me news of their openings, their menu changes and their other happenings, but none has ever been so creative as The Inn at Montross in Montross, Va. The owners wrote to suggest I review their restaurant; in order to tempt me, they sent photos of some specialties.

The stuffed loin of pork was a handsome contrast of orange and green vegetables against pale meat and dark sauce. The lobster gratinee looked generous. The smoked duck breast and the lobster bisque with grilled scallops and crab meat were attractively garnished. But what most caught my attention was a photo labeled "ex lobster gratinee," the plate nearly licked clean. Looks tempting.

THIS SEASON there's a rash of credit card scams. Diners at two different restaurants reported having their card run through the credit card machine twice, thus receiving two bills for the same meal. Tearing up carbons in front of the patron makes a nice show, but the only way to know your card hasn't been used twice is to check your statement each month.

NEW YORK CITY has 151 kosher food facilities, and even Brooklyn has 62. Chicago has 26, Atlanta has a booking agent for kosher bed-and-breakfasts, and Las Vegas has a kosher restaurant with one-armed bandits. Even Salisbury, Md., has a kosher eatery. But the Washington area has probably the lowest number of kosher restaurants for a city of its size. We have two on-campus kosher restaurants (at George Washington University and University of Maryland), Nut House Pizza in Wheaton and the controversial Moshe Dragon in Rockville, which has a new owner and a new name: Royal Dragon.

You can learn about these and the rest of the nearly 800 kosher restaurants, hotels and resorts in North America from the 224-page "Kosher Club Guide." The catch is that it comes only as part of the Kosher Club membership, which at the moment costs $39.95 if ordered over the phone with a credit card. Membership includes bimonthly newsletters to supplement the guide, and discounts at some kosher restaurants as well as hotels and motels. It also sells kosher frozen meals by mail order ("an upgrade of airline meals," co-owner Monica Ostrow calls them). The toll-free phone number is 800/3-KOSHER.

THE WORD is traveling quickly around the country that restaurant prices are dropping. But it doesn't seem to have been absorbed in New York yet.

I noted on the summer menu of Manhattan's Four Seasons restaurant that at lunch the chicken salad (with roasted porcini mushrooms) is $32, the chef's salad is $27, and scrambled eggs with smoked salmon -- prepared tableside -- is $32.50. Washington restaurateurs, please don't take note.

Phyllis C. Richman's restaurant reviews appear Sundays in The Washington Post Magazine.