Stagil Table search for an empty date field

[Jon Kocen]

Using Stagil Table for Jira Data Center on prem.

How do you search for a field that has no date in it?

Mitigation = "ACD{}" brings back any ticket with any Mitigation row that has or doesn't have an ACD filled . 

I have tickets that have 5 Mitigation rows and some have ALL of the ACDs filled in and some have a few ACDs filled in. I would not expect to get the tickets where ALL of the ACDs are filled in, but I am - confusing?