In IDM2 in Policy Builder how could I test if an attribute is being
"cleared" from one Edir driver to the next? I clear an attribute in a tree
which flows through the Subscriber. I want the Publisher in the other tree
to realize this is a clear all values so I can write a rule that will
trigger when this attribute is being cleared.

I have written many rules testing attribute values, just not one to test if
an attribute is getting deleted.