Repeating Section Properties
If a data control has been placed in a Repeating Section, these settings can be used to specify the column heading for the field and optionally compute summary values for the field.
The heading shown for the field in the Repeating Section. By default, the field label is used.
If enabled, summary values will be computed for the field in the Repeating Section. The following values will be computed for the column:
Summary values can be referenced in client-side computations. For example, the summary total for a field called 'Subtotal' in the Repeating Section could be used to define the Calculated field expression for a text box to display the total for items in an order: