This value is valid for any scripts run by any received command. It holds the name of the interface that received the command. It is also set during any events that cause the Interface Error Script to execute.
If an error occurs while running any handler in the Interface Script or in response to anything down stream of a command that was received from an interface this value will also be set prior to executing the Script Error Alert script. You can query it there to get more info for sending an alert or logging more info to help track down scripting issues.
returns text, the name of the receiving interface.