White Tie
This the most formal dress code, often referred to as Ultra Formal. White tie means full dress, tail coat, white bow, vest, dress shirt, cummerbund and patent leather shoes
Black Tie
This means formal. Normally either Tuxedo or Dinner Suit with a black bow tie, dress shirt, cummerbund (optional) and leather shoes. Vests are also commonly worn to add an individual touch.

Formal/Lounge
This usually means the same as black tie, but in most instances a dark suit with formal shirt and tie would be appropriate. You could also wear a dinner jacket with a shirt and no tie.
Something a little formal, but not too much so, where elegance is the number one rule....
Semiformal
Semiformal is possibly the trickiest of all the dress codes and can also be referred to as After Five.
Simple rule to follow: The later the event, the darker and dressier you have to be.
Consider is the formality of the event and also the time of day. This would usually mean that a dinner suit is not required. For an evening event – a dark suit with no tie. For a daytime event – any colour suit with no tie.
Cocktail
This means elegant. Wear a suit with a formal shirt and tie or adventurous and select a shirt that is flamboyant to wear without a tie.

Dressy Casual
Usually neat trousers or dark jeans with a smart collared shirt, a jacket is optional. Casual generally means anything goes.
Just think of this dress code as a dressed-up version of a casual look.
Informal
This can mean the same as casual. However, when associated with a wedding or other special event, some form of decorum and good taste should prevail. A pair of trousers and shirt which are informal, but respectful to the event.
Offers more room for personal expression