Typographic Conventions

A command name or qualified command phrase.

Text displayed by the computer.

A key sequence. A sequence such as Ctrl-x indicates that you must hold down the key labeled Ctrl while you press another key or button.

The name of an environment variable, for example, PATH.

The name of an error, usually returned in the errno variable.

The name of a keyboard key. Return and Enter both refer to the same key.

The defined use of an important word or phrase.

Commands and other text that you type.

The name of a placeholder in a command, function, or other syntax display that you replace with an actual value.

The contents are optional in formats and command descriptions. If the contents are a list separated by |, you must choose one of the items.

The contents are required in formats and command descriptions. If the contents are a list separated by |, you must choose one of the items.

The preceding element can be repeated an arbitrary number of times.

Separates items in a list of choices.