BPM PreProcessing 9.05 Method Directive ? Expression

I found a preprocessing method directive in 9.05.603 I’m trying to get to work in E10.1.400.18. The directive is set up for the Update method of Job Entry. The condition is “the JobHead.Date02 field of the changed row is equal to the ? expression”. What does the “?” mean and what is the equivalent in E10?

I think the ? was like not-set, or null. So in E10 I believe the equivalent, at least in C#, would be JobHead.Date02 == null