How do I implement a comma-separated enumeration of data in a template?

In this case you want the comma or any other separator text to appear only between the records. For this there is the identifier $[HasNextRow], which can be used within a $[Repeat] range. It only outputs the contained document part if the currently viewed data set (line in DV) has a subsequent data set. This condition then applies to all lines in a DV, except for the last line.

Example Template:

A list with fruits: $[DV1.Repeat]$[F10001]$[HasNextRow], $[/HasNextRow]$[/DV1.Repeat]

Output:

A list of fruits: Apple, pear, banana, strawberry