This document provides guidelines for formatting business letters, including: - The physical appearance and formatting of a letter makes the first impression, so letters should be single-spaced, double-spaced between paragraphs, with clear dark print and no errors. - There are five standard styles for arranging letter parts: full-blocked, blocked, semi-blocked, square-blocked, and simplified/AMS. Each has specific guidelines for formatting elements like the dateline, salutation, etc. - Punctuation styles are either open, with no punctuation except in the body, or standard, with colons after the salutation and comma after the closing. Postscripts should generally be avoided.