The following typographical conventions are used in this book:
Indicates new terms, URLs, email addresses, filenames, and file extensions.
Indicates program listings, and is used within paragraphs to refer to program elements such as variable or function names, databases, data types, environment variables, statements, and keywords.
Constant width bold
Shows commands or other text that should be typed literally by the user. Also occasionally used for emphasis in code listings.
Constant width italic
Shows text that should be replaced with user-supplied values or values determined by context.
This icon signifies a tip, suggestion, or general note.
This icon indicates a warning or caution.