Regional rules of dressing are all over the map

? “Black tie,” a seemingly self-explanatory dress code, might have a different definition depending on where you live.

In Los Angeles, the cues come from the red carpet, where originality counts; in Dallas, the bigger the ballgown the better, especially when worn with jewels and stones. And in New York, women, who always check first to see what their friends are wearing, usually end up in something understated.

For Vogue’s July issue, fashion news director Sally Singer asked women from all over the country about their hometown’s fashion rules. She purposely sought out real women who care about their appearance but don’t live and die by runway trends.

The findings include:

“St. Louis is a conservative town and dominated by what I call the ‘country club look,”‘ says Nancy Sachs, a political fund-raiser.

“If you wear long sleeves, especially in South Beach, you feel like a schoolmarm,” says writer Victoria Pesce Elliot of Miami.

“People tend to perceive Detroit as a blue-collar, fashion-oblivious community, but it really isn’t. ‘Understated elegance’ is a good way to describe the way we dress we’re not flamboyant or outrageous,” says Marsha Miro, an art critic and filmmaker in Bloomfield Hills, Mich.

Singer, in a telephone interview, says all of the women, while not slaves to fashion, were definitely interested in their wardrobes and those of their neighbors.

“What I found most interesting was the level of fashion knowledge and the confidence with which they (the women) executed that knowledge,” she says. “They also had the confidence to set rules for themselves.”

The women from New York, Los Angeles, Dallas and Chicago did agree, however, on a handful of uniform dos and don’ts.

Wear suits, they say, only if they simplify your life or if you want to show respect to someone especially if you’re asking that person for a lot of money.

Also:

For workweek cocktails, add an eye-catching accessory to an otherwise work-appropriate outfit.

Do not bare your midriff, even if you are 22 with Pilates abs. “It’s over, it’s gone, grow up,” says Vogue’s style panel.

Wear vintage but don’t be precious about it.

Buy shoes. Then buy more shoes.

Finally, if someone is in fashion doubt, reach for the three “golden lifelines”: a trendy terry tracksuit to walk the dog or pick up the kids; wear your nails short, plain and clear; and invest in a Diane von Furstenberg wrap dress.