Series Group Properties Dialog Box, Variables
Select Variables on the Series Group Properties dialog box to add custom variables to your report. A variable is processed when you first run the report and can be referenced throughout the report. Because the variable is calculated only once, each reference to the variable will always use the same value. This can be useful, for example, for capturing values that can change during run time, like a time stamp in a report header. Variable names must be unique throughout the report.