Within Setup > Global Settings > Service Desk Settings are the following options - "Close Inactive Resolved Incidents" and "Reopen Resolved/Closed Incidents".
Unfortunately, letting Requesters answer whether they agree that an Incident is Resolved allows them to add content to Closed Incidents as well.
Customers who came from the SW WHD application always had this but in moving to SWSD this becomes an issue so a negative enhancement.
Can the "Reopen Resolved/Closed Incidents" be separated so Requesters can answer Incidents with a State of Resolved but not if Closed?