Add the "NOT IN" operator to the Search Builder's search criteria options

The lack of a "NOT IN" restricts the functionality of tags and groups by not allowing the ability to omit certain contacts from the found set. Also having this ability would give Smart Groups more power by dynamically omitting records based on tagging.

Example: if large donors are handled through staff committed to raising funds from these donors, then these large donors are tagged. In the basic donor report provided to volunteers helping with small donation fundraising (telemarketing, etc.) there is a need to omit these tagged large donors.