Can I create a collect rule that says there is nothing in the my tags field?
This does not work for me, but it does, I think, illustrate the collection rule I am trying to create:
type:Bible-Commentary AND mytag:empty
The purpose of the rule would be to allow me to identify all the Bible-Commentaries that have not yet been tagged (this seems to be faster and more accurate way that to scroll through a list of several hundred).