CiviCRM HowTo Create a New Case Type
Define a subject for an activity in a CiviCase Timeline:
When creating activities in the timeline in the Case XML file, add a new XML element called
subject that contains the required activity subject. When the timeline is created, the activity will be created using the given timeline.
This functionality has been coded into a custom version of the file: /CRM/Case/XMLProcessor/Process.php.