Conventions used in this Wikibook:

Italic

Used for file names and directory names. Also used to introduce new terms.

Constant width

Used to indicate commands, command lines, and command line switches.

Constant width italic

Used to indicate user-defined input; the user creates the text.

Constant doremon

width bold

Used in interactive examples to indicate literal user input.

Preformatted text blocks

Used for code blocks and multi-line shell output examples where whitespace matters

[ ]

Brackets surround optional inputs; omit the brackets when supplying these inputs.