This document discusses different styles of writing business letters. It identifies five styles: full block, semi block, indented, hanging, and simplified. Full block style aligns all letter elements flush left. Semi block is similar but indents some lines slightly right. Indented style indents all lines of each paragraph except the first. Hanging indent indents all lines of each paragraph except the first, which is reversed from semi block. Simplified style omits salutation and complimentary close when the recipient's name is unknown.