JQL search if custom field exists

[ToM]

To organize the IT work, I created a Kanban board that includes tasks from all projects boards, incl. the boards of each team member (where the can add there own daily tasks that are not related to any project).

For this "self organization boards" I add a custom field "ticket type" which can be private or public.

I only like to show the public tasks, as private tasks are not part of the IT coordination.

But when I add the filter "ticket type" = private, all projects where this custom field does not exists are no longer shown on the board.

So I tried to find out if I can first filter if the field "ticket type" exists.

I currently did not find a way. 

Any ideas?

[Nic Brough -Adaptavist- · Accepted solution]

This is what it is already doing - when you limit by issue type, there's no point showing the projects that can't have any issues because they don't have the type.

[ToM]

Thank you for the fast answer, but I meanwhile solved the issue by removing the custom field and used security level instead, makes more sense :)