Identifies two or more records (resource instances) that refer 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 as well as the user or organization who establishes the context in which the nature of each linkage is evaluated.

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

Identifies which record considered as the reference to the same real-world occurrence as well as how the items should 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.