THE COVER says it all. Or at least it appears to, on first glance. Just the throat to waist of a buxom teenage student in supertight tee shirt. Superimposed on her chest are the words" litters 101."

Litters, Get it?

"What are you reading?" people ask, making a disapproving face at the same time they eagerly snatch up the book to thumb through it. "Wait-you mean this was written by women."

Of course, this work of humor--which takes the form of a textbook in order to satirize writers, male and female, through the ages could hardly have been written by men. Sometimes adolescent, often crude, nevertheless the humor is undeniably female. Its authors describe the work as "a lock into the women's washroom." Women get to talk about men the way they at so often outraged that men talk about them. There's some angry-sounding stuff in here.

So why the derogatory cover? The ambiguity of the message is one of the central elements of Titters 101: An Introduction to Women's Literature.

DIVIDED INTO chapters on individual "writers," including excerpts from their work, the book parodies everyone from Helen of Troy to Helen Gurley Brown to Anais Nin (who becomes "Anais Zit"), spearing Truman Capote and Norman Mailer '43 along the way. But the barbs aren't just aimed at writers; writers are the convenient vehicle to get to the heart of society itself--and in particular men and women and sex. After all, two of the authors say, "the main motivating force in everyone's life is sex." But about politics--don't satirists have to have politics? Consider, however, these two chapter descriptions:

The Age of Romance and Industry. A new element enters into literature; women writers are accepted on a par with men as long as men don't know they are women.

LILLIANPUTIAN

The Misadventures of Robin Caruso

A young girl puts on men's clothing; slows away on a seafaring vessel; ends up stranded on a desert island without any guys or moisturizer.

If sex is war, whose side are these women on?

"We're like the Saks Fifth Avenue slogan: We are all 'he things you are," says Deanne Stillman, one of the three authors. She and Judy Jacklin, co-author and art director, are on four promoting Titters, and are clearly having a good time.

"Feminist?" the 33-year-old Jacklin makes a face. "I'm a humanist. Feminists--it's like being in the army or something. I'm not quite there."

"We think of ourselves as writers--that's what we do." Stillman, who is 34, says, Jacklin nods. "Feminists are a group who are very active in lots of things, some of which I'm akin to, and some of which I'm not," Jacklin adds.

Pressed nevertheless to explain the cover design, they say simply that it is based on their last book, of which Titters 101 is the sequel, Titters: The First Collection of Humor by Women, was published in 1976 and sold 100,000 copies, they say. So their publisher wanted to play on the recognition. But how do they feel about the accusation of exploitation?