P/N 480-0049-00-13 Preface-3About this GuideTypographical ConventionsProduct Guide ConventionsCertain typographical conventions are used throughout this product guide. See below.• All commands you enter via keystrokes appear in bold (e.g., Press Enter or Press Ctrl-I).• All text commands you enter via Telnet session or command line typing appear in italics (e.g., typeactive).• There are three types of special text that are designed to reveal supplemental information: Note, Warn-ing, and Caution. See below.A NOTE provides additional, helpful information. This information may tell you how to do a certaintask or just be a reminder for how-to’s given in previous sections. (i.e., For a list of valid commands atany time, type ?)A WARNING provides information about how to avoid harming your VoIP equipment or other equip-ment (i.e., Do not stack more than 4 units together.)A CAUTION provides information about how to avoid injury to yourself or to others (e.g., Do not installthe equipment during a lightning storm).