One of the new features of Nagios Core 4.0 is a means for specifying a value for hosts and services to allow for setting a threshold for notification behavior. This is implemented with the
importance directive for hosts and services and the
minimum_importance directive for contacts. This feature is designed to allow some flexibility for deciding how critical problems with specific hosts or services are and, hence, whether to alert different contacts depending on their severity.
For example, it might be appropriate to page a system administrator about a server used for internal development being inaccessible, but not to contact anybody else, as this service being down doesn't involve accountability ...