Identifies two or more records (resource instances) that are referring to the same real-world "occurrence".

Indicates whether the asserted set of linkages are considered to be "in effect".

Need to be able to mark a linkage record as not to be used because it was created in error.

If false, any asserted linkages should not be considered current/relevant/applicable.

Identifies the user or organization responsible for asserting the linkages and who establishes the context for evaluating the nature of each linkage.

"Primary" for the same set of linked resources may be different from different user's/organization's perspectives.

Identifies one of the records that is considered to refer to the same real-world occurrence as well as how the items hould be evaluated within the collection of linked items.

Distinguishes which item is "source of truth" (if any) and which items are no longer considered to be current representations.

The resource instance being linked as part of the group.