This document discusses the parts and formats of business letters. It identifies the three main components as the blocked, semi-blocked, and unblocked/indented formats. The blocked format lines up all text along the left margin. The semi-blocked centers some text in the middle of the page. And the unblocked/indented format indents the first line of paragraphs and centers the subject line. The document also lists the typical parts of a business letter as the sender's address, date, recipient's information, subject, salutation, message body, closing, signature, and designation.