Very similar in etiquette to white tie, just without all that white. Oh, and you can ditch the stiff front shirt in favour of a pleated front or formal white shirt. Tuxedo jackets and matching trousers are your suiting of choice fellas, with a black bow tie and cumberbund to match, optional braces to really get a good fit, cufflinks, black patent shoes and dress socks once again. Ladies, you can keep that formal evening gown if you like, or mix it up with an elegant cocktail dress or your most expensive-looking Little Black Dress.
Creative Black Tie
This dress code option basically just lets you have more fun with your aforementioned black tie ensembles. Add some flavour to your look with statement accessories - such as an embellished clutch or hair piece, and for the guys try out a matching patterned or coloured bow tie and cumberbund combo or wear a black shirt instead of white.
Black Tie Optional
Ooh don't you just hate the word 'optional'? What does that even mean! Again, just think black tie with a few more tweaks to loosen up your look. Instead of a black suit, go for navy or charcoal with a white dress shirt, and wear a pair of leather dress shoes with a matching leather belt. Women can look at more fashion-forward options like dressy separates instead of a cocktail or evening dress.
Semiformal
Similar to black tie optional, this is definitely a more relaxed form of dress but still with a formal element. Have fun with separates and long skirts, ladies - maybe even a cute matching two-piece. And guys, get a bit adventurous with your choice of tie but stick with a dark suit and throw in a vest if you feel so inclined.
Festive
Finally, the lads get to add a bit of colour! With a festive dress code you can have fun with your suiting - perhaps opting for a light grey or beige colourway. You might choose to go tie-less and keep your top button undone - or pick a tie or bow tie that works with the setting of the occasion. Nothing really changes for female attire with this one, though you might choose to rock a pants suit or wear trousers with a dressy top.
Business Formal
Heading away from the party and into the office now, business formal certainly has more restrictions for females, requiring a rather conservative take on the work wardrobe. Suits (pant or skirt), dresses worn with a blazer, stockings in winter and always heels - it often pays to keep your shoulders covered too. Dark business suits are required for men, with a dress shirt, simple tie, leather dress shoes and dark socks, with the option of adding a vest in the same fabric as your suit.
Business Casual
For the slightly more laid-back, yet still corporate environment, men can get away with a sport coat or blazer with trousers or chinos - still no jeans though. You could look at wearing a polo shirt instead of a dress shirt and loafers as a more casual footwear option. Still keeping those shoulders and chests covered, women have a number of options including skirts, dresses, pants, shirts and sweaters - rather than having to go down the formal suit route. Just remember, no matter what the dress code is at your office, always try to play by the rules.
Dressy Casual
For the guys, just follow the instructions for business casual and be done with it - it's pretty much the same type of thing. Want to wear a tie? Go for it! If not, no worries. Women, you've finally got a dress code where you can wear jeans - just make sure you're not wearing a sloppy t-shirt or singlet - smart tops are best.
Casual
The least thought-required dress code of them all. Casual means you can wear jeans guys (so long as they're in good nick with no holes or rips), bermuda shorts, tasteful t-shirts or polo shirts and sneakers (again, make sure they're clean). The same rules apply for girls - jeans, shorts, skirts and t-shirts are all allowed so long as you look neat. And if you want to go one step further, wear a sundress or casual button-down blouse.