The traditional wedding dress is back, in such numbers that even for second marriages, women are opting for white or ivory gowns with flowing trains and veils.

Although purple jumpsuits and barefoot weddings are still the choice of a few, the shift is toward dress and ceremony that are conservative, going along with the general tilt of the country. And along with marriage becoming downright respectable again.

The same reasoning that is prompting women to buy safe, familiar clothes in a tough economy may be working on brides. Investment in bridal paraphernalia (easily $400 for the dress alone) is softened by the thought of putty it away for the next generation. A traditional gown is going to be more appealing in 20 years than a gimmicky style.

With such a swing backward, of course, there are changes. Nothing returns precisely as before. Today's wedding ceremony is often composed by the bride and groom. There is more freedom with flowers. Dresses worn by the support team are more apt to be geared to everyday fashion trends so they can be worn beyond the wedding day.

Patricia Tolley, bridal buyer for Woodward & Lothrop, pegs the biggest jump in traditional weddings from last year to this. "Brides are older . . . so are the attendents, and therefore, so are the dresses in some ways, with their sweetheart or Queen Anne necklines and traditional fabrics such as satin and chiffon year 'round."

Pleated sleeves and big pleated flounce skirts are again popular at Claire Dratch, according to bridal buyer and consultant Pam McNamara.

"They may alter other things about their wedding," said McNamara, "but not the wedding dress."

The bride's choice sets the tone for the rest of the wedding attire. A chapel-length (or one-yard) train, for example, is not quite as formal as the (two-yard) cathedral length.

Many second-time brides are seeking the kind of dresses they never got to wear the first time around. Others, according to McNamara, simply feel it is their day and they can make up the rules, even if they surprise some guests.

Men, say the experts, have been more reluctant than women to go along with the return to classic wedding wear.

According to Bernie Toll, vice president of After Six, the largest formalwear manufacturuer in the world, 90 percent of all the men's formal attire his company provides for weddings is in color, with white, blue, beige and butternut favorities for spring.

"Black is almost nonexistent for spring weddings," maintains Toll.

(Dispite that word, we find it hard not to say here that we give the highest marks to men's wedding attire that starts with black or dark gray, with white shirts. Or even navy blazers for the most informal weddings. One hopeful note: Ruffles are finally fading and wing collars with neat tucks are beginning to catch on.)

For those who want to strike out for some originality in their weddings, it's not a bad idea to know the rules so you know what you're breaking. Here's the original formula from Amy Vanderbilt, as revised by Letitia Baldrige:

Full-dress tailcoat -- Strictly for after-6 p.m. formal weddings.

Formal daytime dress before 6 p.m. -- Black or dark gray cutaway, or long jacket, with gray vest and gray striped pants.

Informal morning or afternoon weddings -- Gray or black stroller with striped trousers or a dark gray, black or navy business suit.

Informal evening weddings -- Black tie with white or black dinner jacket.

If the bride wears a street-length dress, the groom should be in a dark business suit.

Amy Vanderbilt also has a word for guests: Men should always wear dark business suits except for formal evening weddings, when black tie should be the dress, or white tie if related to the couple.

(These rules, by the way, do not vary with the seasons, except, she says, for a white dinner jacket in place of black for warm weather.)

And for those who want to stick to the old rules, try this, according to Emily Post:

"Especially well-dressed bride-grooms have the soles of their shoes blackened with waterproof shoe polish so that when they kneel, their shoes look dark and neat. (One must be sure that the polish is of the kind that will not come off on carpets or rugs.)"