Since every Alertus node (i.e. Alertus Desktop client computer, Alert Beacon, etc.) in a given system has a unique ID, the Alertus server knows how much time has passed since every node has checked in. This information can be used to determine which clients have or have not received an alert message.  Furthermore, both the Alertus Desktop client and Alert Beacons include an acknowledgement feature.  When displaying an alert, the client includes a prominently placed "Acknowledge" button.  Once pressed, this button indicates to the server that a recipient was notified.  After an alert is activated, all of this information is automatically collected, tabulated, and presented in an easy-to-understand format, based on real-world feedback from emergency management personnel.  These reports can be easily accessed from the "Reports" page in the Alertus Activation Software.