Mens Wedding Tuxedos//"What Not to Wear to a Wedding"(Photo: Alison Gootee\The Knot)

Has a wedding invitation ever left you baffled about the dress code? Here's how to make sure your attire doesn't stand out for all the wrong reasons.

When the invite says "White Tie"...
We're talking seriously swanky. Picture red carpet attire or a presidential inaugural ball.
He shouldn't wear: Anything less casual than a tuxedo. You'll fit in better in a jacket with tails, a white vest, and a bow tie.
She shouldn't wear: Anything that couldn't be described as a gown. Look at this as an opportunity to pull out all the stops. Think full-length skirts, dramatic jewelry, and glamorous makeup.

When the invite says "Black Tie"...
While slightly less formal than a white tie affair, a black tie dress code still requires plenty of formality -- and probably means it is an evening wedding.
He shouldn't wear: Again, a tuxedo is the standard here. While you can eschew the bow tie for a smart cravat, avoid light-colored suits, and embrace cummerbunds and patent leather shoes to keep from sticking out.
She shouldn't wear: Anything too short or summery. If you're teetering between outfit options, consult someone close to the bride to figure out the exact formality of the event. Black tie can mean anything from cocktail dresses to long evening gowns, so you want to make sure your outfit suits the venue and vibe of the reception.

When the invite says "Formal" or "Black Tie Optional"...
He shouldn't wear: Anything too over-the-top. While a tuxedo will fit in nicely, a formal dark suit with a dark or neutral-colored tie will also fit the bill. Just leave the top hat at home.
She shouldn't wear: A sundress, sandals, or anything else you could get away with on the beach. While it is okay to swap the gown for a dressy suit or formal cocktail dress, you still want to stick to dressy materials (like chiffon, silk, or taffeta) and dark or jewel tones.

When the invite says "Beach Formal"...
This means the bride and groom still want a formal event, but they're warning you to dress for the elements as well.
He shouldn't wear: Anything that you'll overheat in. A khaki or linen suit and sandals are perfectly acceptable. And feel free to skip the tie.
She shouldn't wear: Floor-length skirts in heavy materials like velvet or tweed. Think what you would wear to a nice dinner out: a knee- or tea-length dress with flat sandals and a relaxed hairstyle (the wind will undo anything too styled anyway).

When the invite says "Semi-formal" or "Dressy Casual"...
If it's an evening reception, go for something in a neutral color; for a daytime affair, light colors and fabrics are entirely appropriate.
He shouldn't wear: An overly stuffy suit. Opt for a suit and tie in an appropriate color for the season and time of day -- like gray wool for an evening or winter wedding, and khaki or seersucker for a summery garden party.
She shouldn't wear: A ball gown or a cotton sundress. Aim for something in the middle, like a cocktail dress or a skirt and top accessorized with statement jewelry.

When the invite says "Casual"...
This isn't the time to bust out your jean shorts and tank top. Shoot for business casual to keep from looking underdressed.
He shouldn't wear: We ruled out jeans and T-shirts. (Yes, that includes tuxedo T-shirts.) Instead, stick to dress pants or khakis with a button-down shirt or polo.
She shouldn't wear: Outrageous makeup or hair. Keep your look natural and breezy. For attire, stick to sundresses, or a skirt or pair of slacks with a nice top.