How to use the "Not On Hold" search filter that is seen when editing the recipients for a hold notice
You want to identify people for a matter who have not been sent a hold notice and add them as recipients to a hold notice.
Resolving the problem
When editing the recipients for a hold notice the Holds search filter under the People in Scope tab has a value "Not On Hold". When selected this search filter will find people from the selected request who were never added as a recipient to notices associated to the request. With the list of people you can then add them as recipients to the hold notice.