---
type: "resource-definitions"
title: "Linkage Definitions"
resource: "Linkage"
---

# Linkage Definitions

<a id="Linkage"></a>

## Linkage
Links records for 'same' item

**Definition:** Identifies two or more records (resource instances) that refer to the same real-world "occurrence".

**Cardinality:** 0..*

**Constraints:** lnk-1 | error | Must have at least two items | item.count()>1

**Mappings:** rim=N/A - RIM doesn't know how to do this; w5=infrastructure.structure


<a id="Linkage.active"></a>

## Linkage.active
Whether this linkage assertion is active or not

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

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

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

**Meaning if Missing:** This resource is generally assumed to be active if no value is provided for the active element

**Cardinality:** 0..1

**Type:** [boolean](/boolean)

**Summary:** true

**Mappings:** w5=FiveWs.status


<a id="Linkage.author"></a>

## Linkage.author
Who is responsible for linkages

**Definition:** Identifies the user or organization responsible for asserting the linkages and establishing the context in which the nature of each linkage is evaluated.

**Cardinality:** 0..1

**Type:** Reference([Practitioner](/Practitioner), [PractitionerRole](/PractitionerRole), [Organization](/Organization))

**Summary:** true

**Mappings:** w5=FiveWs.author


<a id="Linkage.item"></a>

## Linkage.item
Item to be linked

**Definition:** Identifies a member of a set of resource instances considered to refer to the same real-world entity and classifies the role of the resource instance in the set.

**Conditions:** lnk-1

**Cardinality:** 1..*

**Type:** [BackboneElement](/BackboneElement)

**Summary:** true


<a id="Linkage.item.type"></a>

## Linkage.item.type
source | alternate | historical

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

**Cardinality:** 1..1

**Type:** [code](/code)

**Binding:** required:[linkage-type](/valueset-linkage-type)

**Summary:** true


<a id="Linkage.item.resource"></a>

## Linkage.item.resource
Resource being linked

**Definition:** The resource instance being linked as part of the group.

**Cardinality:** 1..1

**Type:** Reference([Resource](/Resource))

**Summary:** true