Notifiers - exclude options

Hi, 

We are getting ALOT of messages since we enabled notifications of workstations. We have been able to tweak it a bit using the thresholds, but it's still quite alot. 

Why is there only an Include option in the notifier, but not an Exclude option ? 
We would like to be able to add excluding options to get notified about everything, but exclude unnecassry strings of text like........iTUNES IS UP TO DATE!