THE AD FOR Mel Krupin's Signature Room showed the familiar Washington restaurateur in a typical pose, with cigar in hand. The only problem, pointed out one reader, was that his cigar was poised over a tray of pastries. Do the waiters at Mel's ask whether you want your pastry smoking or nonsmoking?

And speaking of smoke-free environments, one reader would like to drum up support for "music-free" restaurants. She reported that the background-music habit has become so entrenched that one restaurant continued to play the piped-in music even during the performance of a live band. The management said the piped-in music was for the benefit of diners who were too far away to hear the band. li6

QUESADILLA WARS are heating up on 19th Street NW. First Cactus Jack's opened on the site of Flaps; now American Cafe is opening across the street. And this new American Cafe is expanding its menu to focus on Southwestern cooking, just as its neighbor does. In addition to the usual American Cafe salad sampler, look for black beans galore, updated quesadillas and empanadas and -- an indication that the Italian frenzy may be fading -- Southwestern lasagna with flour tortillas substituting for the noodles.

FIRST THERE WERE crepes, then came fajitas. Next, if restaurateur David Chow has his way, the roll-your-own food trend will be mu shi. He's planning to open Mu Shi Magic on top of his Pan Asian Noodles restaurant on Vermont Avenue. The traditional Chinese pancakes won't stop with the usual pork filling; rather, the fillings will be drawn from all of Southeast Asia, including Thai-style shrimp and scallops, Malaysian-style tomato shrimp with chiles, Korean-style barbecue beef and Japanese-style teriyaki chicken. Even the iced coffee will be offered both Thai and Vietnamese style.

RESTAURATEURS ARE constantly being offered new ways to spend their money. Now a New Jersey company is trying to sign up clients for a MenuFax service. Potential diners will call a toll-free number to request menus from the restaurants of their choice to be sent by fax. Thus, without stepping out of their home or office, diners can see what's available, check prices, compare one menu with another. And if restaurant price wars get underway, they can be conducted by faxes between restaurants. I can't see a big future for all this until someone figures out how to fax tastes.

THE SUBURBANIZATION of Washington restaurants has proceeded at such a pace that individual suburbs are printing their own restaurant directories. I've previously mentioned the Silver Spring and Bethesda directories; now there is an update of the "Gastronome's Guide to Clarendon." This free pamphlet listing 23 restaurants is available at the Clarendon Alliance, 1137 North Highland St., Arlington, VA 22201, in person or by sending a self-addressed stamped envelope.

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