What is formal?
There are four categories of formal:
 
White Tie (or Full Dress)
Classic Black Tie
Morning Wear
Creative Black Tie

Morning Wear

Morning wear is traditionally appropriate for formal functions held before 4pm. Styles include: Grey cutaway tail coat, grey striped or black trousers, white wing or conventional collar shirt, grey or black double breasted vest, grey & white checked or striped cravat or long tie (bow ties are not appropriate).

 
What makes my outfit formal?