looking for logic which would support identifying list members duplicates via conditional formatting. A numbered list display name can be repeated. Looking to highlight (conditional format) those that are replicated.
You can do this in a module by adding a numeric line item with the formula
IF NOT ISFIRSTOCCURRENCE(Display Name, Numbered List) THEN 1 ELSE 0
where Display Name is a text line item that picks up the display name of the numbered list. You can then add conditional formatting on whatever line item you like, based on this numeric line item, and it will identify duplicates for you.