Instance termination script is executed for every terminated (forced by the administrative or the system) workflow instances. This script may be useful for to rollback any Instance Opening Script operations.
When If any error occurred while occurs while executing script workflow, termination is aborted and all operations are also rollbacked also.
In script you can use $Instance to get or set initiated instance properties, $Initiator variable specifies the who is initiated the workflow instance, but variable can be null for the module type tasks. You can also refer to the right panel to list available scripting objects.
Unlike task prework or postwork scripts $Xml variable is attached to the data model root element, not to the pool element.