| The following is a list of the typographical conventions used in this book: -
- Italic
-
Used to indicate new terms, example URLs, filenames, file extensions, directories, program names , and, of course, for emphasis. For example, a path in the filesystem will appear as /Developer/Applications . -
- Constant width
-
Used to show code examples, anything that might be typed from the keyboard, the contents of files, and the output from commands. -
- Constant width italic
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Used in examples and tables to show text that should be replaced with your own user -supplied values. -
- Color
-
The second color is used to indicate a cross-reference within the text, and occasionally to help keep the author awake during late-night writing binges. You should pay special attention to notes set apart from the text with the following icons:  | This is a tip, suggestion, or general note. It contains useful supplementary information about the topic at hand. | |
 | This is a warning or note of caution. When you see one of these, your safety, privacy, or money might be in jeopardy. | |
The thermometer icons, found next to each hack, indicate the relative complexity of the hack:  |
