Backus-Naur Form Syntax
Each graphic syntax diagram in this reference is followed by a link to a text description of the graphic. The text descriptions consist of a simple variant of Backus-Naur Form (BNF) that includes the following symbols and conventions:
Symbol or Convention | Meaning |
---|---|
[ ] |
Brackets enclose optional items. |
{ } |
Braces enclose items only one of which is required. |
| |
A vertical bar separates alternatives within brackets or braces. |
... |
Ellipsis points show that the preceding syntactic element can be repeated. |
delimiters |
Delimiters other than brackets, braces, vertical bars, and ellipses 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. |