^ or Ctrl

Both the ^ symbol and Ctrl represent the Control (Ctrl) key on a keyboard. For example, the key combination ^D or Ctrl-D means that you hold down the Control key while you press the D key. (Keys are indicated in capital letters but are not case sensitive.)

bold font

Commands and keywords and user-entered text appear in bold font.

Italic font

Document titles, new or emphasized terms, and arguments for which you supply values are in italic font.

Courier font

Terminal sessions and information the system displays appear in courier font.

Bold Courier font

Bold Courier font indicates text that the user must enter.

[x]

Elements in square brackets are optional.

...

An ellipsis (three consecutive nonbolded periods without spaces) after a syntax element indicates that the element can be repeated.

|

A vertical line, called a pipe, indicates a choice within a set of keywords or arguments.

[x | y]

Optional alternative keywords are grouped in brackets and separated by vertical bars.

{x | y}

Required alternative keywords are grouped in braces and separated by vertical bars.

[x {y | z}]

Nested set of square brackets or braces indicate optional or required choices within optional or required elements. Braces and a vertical bar within square brackets indicate a required choice within an optional element.

string

A nonquoted set of characters. Do not use quotation marks around the string or the string will include the quotation marks.

< >

Nonprinting characters such as passwords are in angle brackets.

[ ]

Default responses to system prompts are in square brackets.

!, #

An exclamation point (!) or a pound sign (#) at the beginning of a line of code indicates a comment line.