How to exclude a single Metric from email notifications?

We have an Rule Set that creates Incidents for all events for all of our Tier 1 Production databases.

This Rule Set includes an Action to email all team members (shared Inbox).

We get an enormous number of emails for a small number of Metrics and a tiny number of emails for all other Metrics. This makes it somewhat difficult to sort the wheat from the chaff.

I've been able to exclude "Categories=Load" Incidents from the notification Action but am unable to determine exactly which Metrics are being excluded.

I've checked the 12c Database-Related Metric Reference Manual but that isn't any help as it doesn't indicate with "Category" a Metric is in.