Parameters are values that are considered constants to the report program and are not declared. Parameters can be used in expressions and conditions in place of a field or variable name. The syntax for a parameter is:
$internalname
There are several predefined parameters. They are:
$page the current page number
$line the current page line number
$column the current column number
$todays_date the date the report program was started
$todays_time the time the report program was started
$TRUE a value which always evaluates to true.
$FALSE a value which always evaluates to false.
If the parameter is not one of these special parameters, the Report Writer will assume that there is a shell parameter with a name of internalname and will use the value of that parameter. Using this mechanism, it is possible to pass parameters to a report program.