Some of the programming syntax in this book uses type
fonts to denote different elements:
Items shown in UPPERCASE letters indicate key elements that
must be typed exactly as shown.
Items shown in lowercase letters indicate user-supplied variables
for which you must substitute appropriate names or values. The variables
begin with a letter and can include hyphens, numbers, or the underscore
character (_).
The term digit indicates that a digit (0 through 9)
should be substituted.
The term do-group indicates that a do-group should
be substituted.
Underlined items indicate default
options.
Examples are shown in monocase type.
Unless otherwise indicated, separate repeatable items from each
other by one or more blanks.
Note:
Any symbols shown that are not purely notational,
as described in How to read the notational symbols, are part of the programming
syntax itself.
For an example of programming syntax that follows these conventions,
see Example of notation.