Other books may tell you how to dress successfully, how to dress chic, or how to dress rich. Only this book tells you how to dress sexy. --"Dressing Sexy: Simple Tips for a Total Look that Makes Conversations Stop and Heads Turn" by Barbara Burgdorf with Sue Nirenberg

. . . .Dressing to succeed in business and dressing to be sexually attractive are almost mutually exclusive.--"The Woman's Dress for Success Book" by John T. Molloy

What's going on?

It's 1981; Congress still hasn't ratified the Equal Rights Amendment; women are still fighting for salaries equal to male counterparts'; there's still lots of bedroom-vs.-boardroom innuendo . . . and along comes the Burgdorf-Nirenberg book, not on dressing seriously, but, seriously, on dressing sexy.

Not that we all went along with Molloy's case for suits, but this latest is enough to push back The Cause 10 years. Consider some of the -- among something like 100 -- "ways to make heads turn":

If you send out signals of competence and authority, cancel 'em.

Remember that a belt with a big buckle in the back is a real turn-on.

Never wear a crisp hairdo.

If you must wear panty hose, buy the kind with rhinestone flecks or mock seams.

In the office, be conscious of your body even when they think you are thinking about office maneuverings.

Try to achieve the after-5 look before 5.

The idea for the book (Fireside, Simon and Schuster, $5.95), says Burgdorf of Hollywood, came to her "mostly from working with actresses in film. Actresses are people, they aren't models, and of course, a lot of directors want their actresses to look sexy.

"I began to realize that there was a need for it the book since Cosmo and all the other magazines are pushing this, but nobody seems to be getting it.

"There are a lot of women around who want to dress sexy but don't know how," says Burgdorf, who as a costume designer for television commercials has dressed Carol Lawrence, Lee Remick and Angie Dickinson.

"With the book, they can look up what are sexy looks, as opposed to what fashion says you should buy and use it as a guideline."

(And be privy to such sagacities as "anthropologists and psychologists insist the toe clefts are a miniature version of the bosom cleft.")

For you Washington women who can't wait to get with it, a la California's Burgdorf and New York's Nirenberg (she's a publicist for Warner Books), you'll have to throw out your L.L. Bean catalogue, learn to "strut" instead of "stride," doff those oxford shirts for camisoles, forget button earrings and take on hoops.

Dressing sexy at the office, they concede, is "the greatest challenge of your life . . . but it's not easy.

"Daytime suits and separates -- and even dresses -- are designed to cover, camouflage and conceal. One plunge too deep, one slit too high and you might find yourself in the personnel office for a lecture on dress code."

Although Nirenberg concedes that wearing business suits without blouses is more apt to put the boss in pursuit of you, than you in his seat of power, she practices what she preaches. "I like to be a sex object. I think it's just fine, and I will be when I can be."

Even John Molloy, the best-selling writer on "dressing for success," succumbs in an interview. He'll draw your attention to his chapter on "Dressing to Attract Men."

"I told my wife that I was going to leave the chapter out, that it would come out sexist," he says. But his wife had the last word: "Don't be stupid, every woman wants to know."