I hold that the parentheses are by far the most important parts of a non-business letter.
D. H. LawrenceAir Hostess: [kiss-off letter] Change of flight. Your plane cancelled. Here's your key. Bye.
Chungking ExpressGeneral Tadamichi Kuribayashi: A day will come when they will weep and pray for your souls.
Letters from Iwo Jima