Crystal Reports for Rational Application Developer Designer Guide
Subtotaling
A subtotal is used to total part of a
series of numbers. For example, you may want to create report that provides a
total of last year's sales for each country in addition to the grand total of
last year's sales.
Note: If you are creating a
subtotal using database tables that are grouped in a one-to-many linking
relationship, you may need to use a running total instead of a subtotal.