JQL

[Harsha Vardhan Doddi]

 In the below example, I am getting the logic why assignee is empty is used. Can anyone help with the logic behind it?

Find all issues where the Assignee is not Jack, Jill, or John:

• assignee not in (Jack,Jill,John) or assignee is empty

[Tansu Akdeniz]

Hi @Harsha Vardhan Doddi 

It returns all issues where assignee is not Jack, Jill, or John (doesn't include unassigned one's)

assignee not in (Jack,Jill,John)

It returns the first query + unassigned issues:

 assignee not in (Jack,Jill,John) or assignee is empty

Best 

[Jack Brickey]

Yes. On can make an argument that if the issue is unassigned then neither Jack, Jill nor John are assign to the issue. 

[Ignacio Pulgar]

Exactly. It's a little bit counterintuitive, but assignee != username does not include issues where that the assignee field were empty.

The same is true for any other fields.

Regards