WowAce

What is the enhancement in mind? How should it look and feel?
In the boolean operator dropdown for meta rules, two new options would be available "And not" and "or not"

Please provide any additional information below.
Several times now I've wanted to exclude anything accepted by a different filter.  While I can (and have) just duplicate the previous filter and flip its sense (now that I can test against caster unknown), it seems like a more generic option would be possible.

The specific instance I have now (that prompted me to add the ticket) is a list of debuffs which I want to treat as uncurable even though they are curable.  I would like to include them in my "uncurable boss debuffs" filter and exclude them from my "curable debuffs" debuff highlight.  The way I did that is to create a whitelist for the debuff filter and a blacklist for the highlight filter.  I'd rather use the same whitelist for both.

Very similar to ticket 234 which was declined. However your new example situation might be better than mine. :)

Your proposed solution isn't particularly desirable because then the first filter in the meta filter still couldn't be reversed. Unless of course the first option got a dropdown that was just blank and then not. Alternatively, I could create a new filter type that was just a reversal of another filter.

I'll think on this some more.

Yeah, you'd have to use True "AND NOT" Rule, which is a bit cumbersome. A column of "Not" checkboxes at the front of each rule would achieve both goals, but that could be confusing as well. Ah well, something to keep in mind.

So having thought about this more, I'm thinking perhaps the best way is to make a new filter type that is just a Not filter type that takes another filter and reverses it. I know we've got an issue with the number of filters somewhat exploding, but I think the actual need for the not filter is somewhat limited since most filters already have a way to configure them one way or the other. However, it should offset the need to entirely duplicate a whitelist in those cases.

http://www.wowace.com/addons/pitbull4/tickets/786-negation-aura-filter-operator/
Was another dup of this.