The following typographical conventions are used in this book:

Italic: Indicates new terms, example URLs, email addresses, filenames, file extensions, pathnames, directories, and Unix utilities.
Constant width: Indicates commands, options, switches, variables, attributes, keys, functions, types, classes, namespaces, methods, modules, properties, parameters, values, objects, events, event handlers, XML tags, HTML tags, macros, the contents of files, or the output from commands.
Constant width bold: Shows commands or other text that should be typed literally by the user, and is used to emphasize code in examples.
Constant width italic: Shows text that should be replaced with user-supplied values. In some cases where text is already italicized, user-supplied values are shown in angled brackets (< >)

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