Request ID : 0001 comes in and then replied by one of the Support Guy (There's a variable $RequestID tagged on the reply) on the other shift, another Request ID: 0023 came in and was replied by another support guy (another RequestID tagged on the reply)
On another day, one Support Guy saw both requests has the same issue so he merged it. Request IDs: 0001 and 0023 are now in one request (0001 as the parent Request)
a Requester called up to followup on the Request ID: 0023
When searching for that Request ID, cant find it. (Blank) Searching for the Parent Request ID has no problems.