This document provides information on how to write formal letters, including their structure and key components. It discusses addressing the recipient, including their name and address. The body of the letter should include a topic, reason for writing, and contact information. Letters should be signed off with a complimentary close such as "Yours faithfully" or "Yours sincerely" depending on if the recipient's name is known. Examples of different types of formal letters like letters of inquiry, application, and complaint are also mentioned. The overall structure of a formal letter involves the address, date, salutation, body, complimentary close, and sender.