LinkageType

Used to distinguish different roles a resource can play within a set of linked resources

This code system http://hl7.org/fhir/linkage-type defines the following codes:

Code	Display	Definition
source	Source of truth	The record represents the "source of truth" (from the perspective of this Linkage resource) for the underlying event/condition/etc.
alternate	Alternate record	The record represents the alternative view of the underlying event/condition/etc. The record may still be actively maintained, even though it is not considered to be the source of truth.
historical	Historical/obsolete record	The record represents an obsolete record of the underlyng event/condition/etc. It is not expected to be actively maintained.