This case-sensitive code system http://hl7.org/fhir/us/medmorph/CodeSystem/us-ph-report-initiation-types defines the following codes in a Grouped By heirarchy:

Code	Display	Definition
subscription-notification	Indicates a report was initiation based on a Subscription Notification.	Indicates that a report creation was initiated based on a notification to a subscription topic.
timer-notification	Indicates a report was initiation based on a Subscription Notification.	Indicates that a report creation was initiated based on a timer expiration. The timer can be absolute or a relative timer.
manually-initiated	Indicates a report was initiated to a manual action by the provider.	Indicates that a report creation was initiated manually by a provider.
alternately-initiated	Indicates a report was initiated in an alternate way by the provider.	Indicates that a report creation was initiated in an alternate way by the provider.