The following is a list of the typographical conventions used in this book:
Is used for file and directory names, program and command names, command-line options, email addresses and path names, site names, and all new terms.
Constant Width
Is used in examples to show the contents of files or the output from commands, to indicate environment variables and keywords that appear in code, and for machine names, hostnames, usernames, IDs, and Emacs commands.
Constant Width Bold
Is used in examples to show commands or other text that should be typed literally by the user.
Constant Width Italic
Is used to indicate variable options, keywords, or text that the user is to replace with an actual value.