Backus-Naur Form Syntax
The syntax in this reference is presented in a simple variation of Backus-Naur Form (BNF) that uses the following symbols and conventions:
Symbol or Convention | Description |
---|---|
[ ] |
Brackets enclose optional items. |
{ } |
Braces enclose a choice of items, only one of which is required. |
| |
A vertical bar separates alternatives within brackets or braces. |
... |
Ellipses indicate that the preceding syntactic element can be repeated. |
delimiters |
Delimiters other than brackets, braces, and vertical bars must be entered as shown. |
boldface |
Words appearing in boldface are keywords. They must be typed as shown. (Keywords are case-sensitive in some, but not all, operating systems.) Words that are not in boldface are placeholders for which you must substitute a name or value. |