This document provides information and guidelines for writing both formal and informal letters, including:
1) The definition of a formal letter, intended for professionals or non-friends/family, versus an informal letter for friends/family.
2) Guidelines for the format of a formal letter including address, date, salutation, content, and closing.
3) Differences between American and British letter writing styles.
4) Samples of abbreviations used and guidelines for an informal letter format.
5) Samples of a formal and informal letter.