I'm sure this is easy, but I can't get it working. I have a date field and I need a report filtered to show when that field is empty. I've tried :

?action_daterequired=null

?action_daterequired==null

When filtering in the menu it has the IsEmpty in the drop down so I've tried that too - nothing is working

I know it's obvious, please someone put me out of my misery