A TRUE ROYAL SHE MAY BE, BUT ENGLAND'S Princess Margaret, poor thing, is no belle. During a 1984 Dallas visit, the Queen's kid sister tripped over a slew of Southern proprieties in a single stroll across her host's living room. Wearing a pink chiffon dress at midday, with pink shoes that did not quite match her outfit, the Princess carried a lighted cigarette in her hand. Such transgressions are tantamount to original sin in Southern Belle—dom, which is why Maryln Schwartz titled her new book A Southern Belle Primer, or Why Princess Margaret Will Never Be a Kappa Kappa Gamma. It's a surprise hit, with 200,000 copies in print. Says Schwartz, a columnist at the Dallas Morning News: "Southern women enjoy laughing at themselves."

The unmarried Schwartz, 47, was raised in Mobile, Ala., the daughter of an accountant, and studied English at the University of Georgia. She went to work as a reporter in Mobile, joining the Dallas paper in 1969. ("I've covered everything from the Super Bowl to the Gary Gilmore execution," she says. "At both, people were yelling, 'Kill him! Kill him!' ")

During two years of interviewing belles for her book, she says, "I realized that I had some of the same traits." In fact, belledom is more a state of mind than a social pedigree, though certain cultural signals do help you know one when you see one. The Primer describes a world in which a woman may be ostracized for putting dark meat in her chicken salad or scarred by failing to pledge the right sorority. It's a world in which family is all. The night the U.S. first bombed Baghdad. Schwartz says, a belle friend called to ask whether the State Department spokeswoman, Margaret Tutwiler, "was one of the Birmingham Tutwilers or one of the Montgomery Tutwilers." Says Schwartz with amazement: "That's all she wanted to know, right in the middle of World War III."