8. Conventions
The following conventions are used in this book:
Constant Width is used for:
Code examples and fragments
Anything that might appear in an HTML document, including element names, tags, attribute values, entity references, and processing instructions
Anything that might appear in a program, including keywords, operators, method names, class names, commands, and literals
Constant-Width Bold is used for:
User input in code examples
To highlight certain code in examples
Italics is used for:
New terms where they are defined
Host and domain names (http://www.mozdev.org/)
URLs (http://books.mozdev.org/index.html)
Interface names and variable names
Constant Width Italic is used for replaceable items, such as variables or optional elements, within syntax lines of code.
You should pay special attention to notes set apart from the text with the following icons:
 | This is a tip, suggestion, or a general note. It contains useful supplementary information about the topic at hand. |
Significant code fragments, complete programs, and documents are generally placed into a separate paragraph like this:
<?xml version="1.0"?>
<!DOCTYPE window>
<window
xmlns:html="http://www.w3.org/1999/xhtml"
xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
</window>