When pulling Access data together into a meaningful format, you may find that reports repeat data. Depending on how you're using the data, you may or may not want to display those duplicate values. Even properly normalized tables won't eliminate duplicates in a report, like this one:
Now, it's normal to display repetitive values on the many side of a relationship, but not on the one side, as this report does. Fortunately, hiding duplicates is just a control property away. With the report in Design view, double-click the control that's displaying duplicate values and set the Hide Duplicates property to Yes to hide duplicates.
The truth is that I had to force Access to display the duplicate values because the report wizards are so smart that they hide duplicate values on the one side of a one-to-many relationship for you. However, you won't always use a wizard; you'll want to know how to hide duplicates yourself. Perhaps more important, you'll want to know how to unhide duplicate values when you don't want them hidden.