There is a setting on the section to 'Suppress blank', if you right-click on the section header and choose Properties from the pop-up menu. This means if the entire section is blank, it will be suppressed. If you have a label (like 'Reference #') in the section, this will cancel the blank section suppression.

- How have you formatted your Serial # section in the specification? Are there 5 Serial number sections with 1 serial number field in each? Or is there a single Serial # section that is 5 rows high and all 5 serial number fields are there?

To take advantage of the blank suppression feature, you would need to have 5 serial number sections, each with a height of one row. You would put the Reference # text label and the first serial number field in the first section. Then the second serial number field in the second section, and so on. Format sections 2-5 with the 'Suppress blank' option.

This worked for me (not printing any extra blank rows for unused serial numbers).