The scope of a simple non-unique aggregate is determined by the context in which it is specified. For example, if you specify sum (salary) in the footer for the report, it refers to the sum of salary for all rows read in the report. If you specify sum (salary) in the page footer, it refers to the sum of salary for all rows that were processed during the printing of each page. If specified in the footer for a break in department, sum (salary) refers to the sum of salary for all rows in each department.

You can specify simple aggregates only in the .footer section for breaks, because these calculations are intended to provide summary information.