This document discusses different styles of writing business letters. It identifies five common styles: full block style, semi block style, indented style, hanging style, and simplified style. Full block style aligns all letter elements flush left. Semi block style indents some elements like the return address and signature slightly right of center. Indented style justifies the left margin except for indented elements like return address. Hanging indented style indents all lines after the first in a paragraph. Simplified style omits salutation and closing when the recipient's name is unknown.