NameFlagsCard.TypeDescription & Constraintsdoco
.. Linkage ΣDomainResourceLinks records for 'same' item
... author Σ0..1Reference(Practitioner | Organization)Who is responsible for linkages
... item Σ1..*BackboneElementItem to be linked
.... type Σ1..1codesource | alternate | historical
LinkageType (Required)
.... resource Σ1..1Reference()Resource being linked

doco Documentation for this format