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. |