ConceptMap

A statement of relationships from one set of concepts to one or more other concepts - either concepts in code systems, or data element/data element concepts, or classes in class models.

Schema

Properties

Name	Required	Type	Description
url		uri	Canonical identifier for this concept map, represented as a URI (globally unique) Details An absolute URI that is used to identify this concept map when it is referenced in a specification, model, design or an instance; also called its canonical identifier. This SHOULD be globally unique and SHOULD be a literal address at which at which an authoritative instance of this concept map is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the concept map is stored on different servers. Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred. Multiple instances may share the same URL if they have a distinct version. The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author. Considerations for making this decision are found in [Technical and Business Versions](resource.html#versions). In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the [meta.source](resource.html#meta) element to indicate where the current master source of the resource can be found.
identifier		Identifier	Additional identifier for the concept map Details A formal identifier that is used to identify this concept map when it is represented in other formats, or referenced in a specification, model, design or an instance. Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, and can then identify this concept map outside of FHIR, where it is not possible to use the logical URI.
version		string	Business version of the concept map Details The identifier that is used to identify this version of the concept map when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the concept map author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence. There may be different concept map instances that have the same identifier but different versions. The version can be appended to the url in a reference to allow a reference to a particular business version of the concept map with the format [url]|[version].
name		string	Name for this concept map (computer friendly) Details A natural language name identifying the concept map. This name should be usable as an identifier for the module by machine processing applications such as code generation. The name is not expected to be globally unique. The name should be a simple alphanumeric type name to ensure that it is machine-processing friendly.
title		string	Name for this concept map (human friendly) Details A short, descriptive, user-friendly title for the concept map. This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc.
status	✓	code	draft | active | retired | unknown Details The status of this concept map. Enables tracking the life-cycle of the content. Allows filtering of concept maps that are appropriate for use versus not.
experimental		boolean	For testing purposes, not real usage Details A Boolean value to indicate that this concept map is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage. Allows filtering of concept maps that are appropriate for use versus not.
date		dateTime	Date last changed Details The date (and optionally time) when the concept map was published. The date must change when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the concept map changes. Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the concept map. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.
publisher		string	Name of the publisher (organization or individual) Details The name of the organization or individual that published the concept map. Usually an organization but may be an individual. The publisher (or steward) of the concept map is the organization or individual primarily responsible for the maintenance and upkeep of the concept map. This is not necessarily the same individual or organization that developed and initially authored the content. The publisher is the primary point of contact for questions or issues with the concept map. This item SHOULD be populated unless the information is available from context.
contact		ContactDetail[]	Contact details for the publisher Details Contact details to assist a user in finding and communicating with the publisher. May be a web site, an email address, a telephone number, etc.
description		markdown	Natural language description of the concept map Details A free text natural language description of the concept map from a consumer's perspective. The description is not intended to describe the semantics of the concept map. The description should capture its intended use, which is needed for ensuring integrity for its use in models across future changes.
useContext		UsageContext[]	The context that the content is intended to support Details The content was developed with a focus and intent of supporting the contexts that are listed. These contexts may be general categories (gender, age, ...) or may be references to specific programs (insurance plans, studies, ...) and may be used to assist with indexing and searching for appropriate concept map instances. When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.
jurisdiction		CodeableConcept[]	Intended jurisdiction for concept map (if applicable) Details A legal or geographic region in which the concept map is intended to be used. It may be possible for the concept map to be used in jurisdictions other than those for which it was originally designed or intended.
purpose		markdown	Why this concept map is defined Details Explanation of why this concept map is needed and why it has been designed as it has. This element does not describe the usage of the concept map. Instead, it provides traceability of ''why'' the resource is either needed or ''why'' it is defined as it is. This may be used to point to source materials or specifications that drove the structure of this concept map.
copyright		markdown	Use and/or publishing restrictions Details A copyright statement relating to the concept map and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the concept map. Frequently the copyright differs between the concept map and codes that are included. The copyright statement should clearly differentiate between these when required.
source[x]		uri, canonical	The source value set that contains the concepts that are being mapped Details Identifier for the source value set that contains the concepts that are being mapped and provides context for the mappings. Should be a version specific reference. URIs SHOULD be absolute. If there is no source or target value set, there is no specified context for the map (not recommended). The source value set may select codes from either an explicit (standard or local) or implicit code system.
target[x]		uri, canonical	The target value set which provides context for the mappings Details The target value set provides context for the mappings. Note that the mapping is made between concepts, not between value sets, but the value set provides important context about how the concept mapping choices are made. Should be a version specific reference. URIs SHOULD be absolute. If there is no source or target value set, the is no specified context for the map.
group		ConceptMapGroup[]	Same source and target systems Details A group of mappings that all have the same source and target system.
id		string	Unique id for inter-element referencing Details Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
extension		Extension[]	Additional content defined by implementations Details May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
modifierExtension		Extension[]	Extensions that cannot be ignored even if unrecognized Details May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself). There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
source		uri	Source system where concepts to be mapped are defined Details An absolute URI that identifies the source system where the concepts to be mapped are defined. This is not needed if the source value set is specified and it contains concepts from only a single system.
sourceVersion		string	Specific version of the code system Details The specific version of the code system, as determined by the code system authority. The specification of a particular code system version may be required for code systems which lack concept permanence.
target		uri	Target system that the concepts are to be mapped to Details An absolute URI that identifies the target system that the concepts will be mapped to. This is not needed if the target value set is specified and it contains concepts from only a single system. The group target may also be omitted if all of the target element equivalence values are 'unmatched'.
targetVersion		string	Specific version of the code system Details The specific version of the code system, as determined by the code system authority. The specification of a particular code system version may be required for code systems which lack concept permanence.
element	✓	ConceptMapGroupElement[]	Mappings for a concept from the source set Details Mappings for an individual concept in the source to one or more concepts in the target. Generally, the ideal is that there would only be one mapping for each concept in the source value set, but a given concept may be mapped multiple times with different comments or dependencies.
id		string	Unique id for inter-element referencing Details Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
extension		Extension[]	Additional content defined by implementations Details May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
modifierExtension		Extension[]	Extensions that cannot be ignored even if unrecognized Details May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself). There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
code		code	Identifies element being mapped Details Identity (code or path) or the element/item being mapped.
display		string	Display for the code Details The display for the code. The display is only provided to help editors when editing the concept map. The display is ignored when processing the map.
target		ConceptMapGroupElementTarget[]	Concept in target system for element Details A concept from the target value set that this concept maps to. Ideally there would only be one map, with equal or equivalent mapping. But multiple maps are allowed for several narrower options, or to assert that other concepts are unmatched.
id		string	Unique id for inter-element referencing Details Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
extension		Extension[]	Additional content defined by implementations Details May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
modifierExtension		Extension[]	Extensions that cannot be ignored even if unrecognized Details May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself). There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
code		code	Code that identifies the target element Details Identity (code or path) or the element/item that the map refers to.
display		string	Display for the code Details The display for the code. The display is only provided to help editors when editing the concept map. The display is ignored when processing the map.
equivalence	✓	code	relatedto | equivalent | equal | wider | subsumes | narrower | specializes | inexact | unmatched | disjoint Details The equivalence between the source and target concepts (counting for the dependencies and products). The equivalence is read from target to source (e.g. the target is 'wider' than the source). This element is labeled as a modifier because it may indicate that a target does not apply.
comment		string	Description of status/issues in mapping Details A description of status/issues in mapping that conveys additional information not represented in the structured data.
dependsOn		ConceptMapGroupElementTargetDependsOn[]	Other elements required for this mapping (from context) Details A set of additional dependencies for this mapping to hold. This mapping is only applicable if the specified element can be resolved, and it has the specified value.
id		string	Unique id for inter-element referencing Details Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
extension		Extension[]	Additional content defined by implementations Details May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
modifierExtension		Extension[]	Extensions that cannot be ignored even if unrecognized Details May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself). There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
property	✓	uri	Reference to property mapping depends on Details A reference to an element that holds a coded value that corresponds to a code system property. The idea is that the information model carries an element somewhere that is labeled to correspond with a code system property.
system		canonical	Code System (if necessary) Details An absolute URI that identifies the code system of the dependency code (if the source/dependency is a value set that crosses code systems).
value	✓	string	Value of the referenced element Details Identity (code or path) or the element/item/ValueSet/text that the map depends on / refers to.
display		string	Display for the code (if value is a code) Details The display for the code. The display is only provided to help editors when editing the concept map. The display is ignored when processing the map.
product		[]	Other concepts that this mapping also produces Details A set of additional outcomes from this mapping to other elements. To properly execute this mapping, the specified element must be mapped to some data element or source that is in context. The mapping may still be useful without a place for the additional data elements, but the equivalence cannot be relied on.
unmapped		ConceptMapGroupUnmapped	What to do when there is no mapping for the source concept Details What to do when there is no mapping for the source concept. "Unmapped" does not include codes that are unmatched, and the unmapped element is ignored in a code is specified to have equivalence = unmatched. This only applies if the source code has a system value that matches the system defined for the group.
id		string	Unique id for inter-element referencing Details Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
extension		Extension[]	Additional content defined by implementations Details May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
modifierExtension		Extension[]	Extensions that cannot be ignored even if unrecognized Details May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself). There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
mode	✓	code	provided | fixed | other-map Details Defines which action to take if there is no match for the source concept in the target system designated for the group. One of 3 actions are possible: use the unmapped code (this is useful when doing a mapping between versions, and only a few codes have changed), use a fixed code (a default code), or alternatively, a reference to a different concept map can be provided (by canonical URL).
code		code	Fixed code when mode = fixed Details The fixed code to use when the mode = 'fixed' - all unmapped codes are mapped to a single fixed code.
display		string	Display for the code Details The display for the code. The display is only provided to help editors when editing the concept map. The display is ignored when processing the map.
url		canonical	canonical reference to an additional ConceptMap to use for mapping if the source concept is unmapped Details The canonical reference to an additional ConceptMap resource instance to use for mapping if this ConceptMap resource contains no matching mapping for the source concept.

Search Parameters

Name	Type	Description	Expression
context	token	A use context assigned to the concept map	ConceptMap.useContext.value as CodeableConcept
context-quantity	quantity	A quantity- or range-valued use context assigned to the concept map	ConceptMap.useContext.value as Quantity | ConceptMap.useContext.value as Range
context-type	token	A type of use context assigned to the concept map	ConceptMap.useContext.code
date	date	The concept map publication date	ConceptMap.date
description	string	The description of the concept map	ConceptMap.description
jurisdiction	token	Intended jurisdiction for the concept map	ConceptMap.jurisdiction
name	string	Computationally friendly name of the concept map	ConceptMap.name
publisher	string	Name of the publisher of the concept map	ConceptMap.publisher
status	token	The current status of the concept map	ConceptMap.status
title	string	The human-friendly name of the concept map	ConceptMap.title
url	uri	The uri that identifies the concept map	ConceptMap.url
version	token	The business version of the concept map	ConceptMap.version
context-type-quantity	composite	A use context type and quantity- or range-based value assigned to the concept map	ConceptMap.useContext
context-type-value	composite	A use context type and value assigned to the concept map	ConceptMap.useContext
identifier	token	External identifier for the concept map	ConceptMap.identifier
dependson	uri	Reference to property mapping depends on	ConceptMap.group.element.target.dependsOn.property
other	reference	canonical reference to an additional ConceptMap to use for mapping if the source concept is unmapped	ConceptMap.group.unmapped.url
product	uri	Reference to property mapping depends on	ConceptMap.group.element.target.product.property
source	reference	The source value set that contains the concepts that are being mapped	ConceptMap.source as canonical
source-code	token	Identifies element being mapped	ConceptMap.group.element.code
source-system	uri	Source system where concepts to be mapped are defined	ConceptMap.group.source
source-uri	reference	The source value set that contains the concepts that are being mapped	ConceptMap.source as uri
target	reference	The target value set which provides context for the mappings	ConceptMap.target as canonical
target-code	token	Code that identifies the target element	ConceptMap.group.element.target.code
target-system	uri	Target system that the concepts are to be mapped to	ConceptMap.group.target
target-uri	reference	The target value set which provides context for the mappings	ConceptMap.target as uri

Inherited Properties

Name	Required	Type	Description
id		string	Logical id of this artifact Details The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes. The only time that a resource does not have an id is when it is being submitted to the server using a create operation.
meta		Meta	Metadata about the resource Details The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content might not always be associated with version changes to the resource.
implicitRules		uri	A set of rules under which this content was created Details A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc. Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of it's narrative along with other profiles, value sets, etc.
language		code	Language of the resource content Details The base language in which the resource is written. Language is provided to support indexing and accessibility (typically, services such as text to speech use the language tag). The html language tag in the narrative applies to the narrative. The language tag on the resource may be used to specify the language of other presentations generated from the data in the resource. Not all the content has to be in the base language. The Resource.language should not be assumed to apply to the narrative automatically. If a language is specified, it should it also be specified on the div element in the html (see rules in HTML5 for information about the relationship between xml:lang and the html lang attribute).
text		Narrative	Text summary of the resource, for human interpretation Details A human-readable narrative that contains a summary of the resource and can be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety. Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.
contained		Resource[]	Contained, inline Resources Details These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, and nor can they have their own independent transaction scope. This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags In their meta elements, but SHALL NOT have security labels.
extension		Extension[]	Additional content defined by implementations Details May be used to represent additional information that is not part of the basic definition of the resource. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
modifierExtension		Extension[]	Extensions that cannot be ignored Details May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions. Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself). There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

Usage

A concept map defines a mapping from a set of concepts defined in a code system (commonly referred to as the "system") to one or more concepts defined in other code systems. In the mapping context, a system can be a typical code system based on a recognized standard or local terminology (in any of its forms), or in some cases it may be an "implicit" code system that is not based on a recognized terminology but still represents a set of "concepts" that can be usefully mapped. Mappings are one way - from the source to the target system. In many cases, the reverse mappings are valid, but this cannot be assumed to be the case.

Mappings between code system concepts are only intended to be defined in the context of a particular business usage. The business use case is normally defined by the specification of the source and target value sets. The mappings may be useful in other contexts, but this must be determined based on the context of use and meaning; it cannot be taken for granted automatically. An example where the usage context is important for choosing the correct mapping is mapping from a clinical terminology (e.g. SNOMED CT) to a classification (e.g. ICD-10) for either data analysis or billing. Mappings in the data analysis context would be targeted for an appropriate classification (often at a higher level), whereas in the billing context there may be specific requirements to be met (e.g. leaf level codes only) that could result in multiple mappings for a single source concept and then require additional information beyond the source concept itself in order to select the correct final mapping.

Note that all code systems (explicit or implicit) represented in FHIR have URI identifiers for value sets (also either explicit or implicit) that include the entire code system, and these "all codes" value sets can be used for mappings that are valid in all use contexts that are appropriate for the code system.

Each mapping for a concept from the source to target system includes an equivalence property that specifies how similar the mapping is (or, in some cases, that there is no valid mapping). There is one element for each concept or field in the source value set or system that needs to be mapped. Each source concept may have multiple targets:

• because there are multiple possible mappings (e.g., ambiguous)
• to specify a correct map, and specify other mappings as invalid
• when there are multiple mappings depending on the values of other elements (dependsOn)

There SHOULD be at least one target for each element, but some incomplete concept maps might not have a target for each concept.

A key concept for the ConceptMap resource is the $translate operation. This operation is a formal definition of an API by which a terminology server can allow clients to ask for a translation to be done based on the content in the ConceptMap resource. As such it also provides useful perspective on the operational use of ConceptMap resources in any context.

Relationships

While ConceptMap resources are not referred to directly from any other resource, they may be included and used in ImplementationGuide resources, and provide background knowledge that is useful in many contexts, including operations defined in this specification.

In addition to ConceptMap, there is also the StructureMap resource. The ConceptMap resource defines relationships between concepts in their own right, along with grading of their equivalencies, while the StructureMap defines an executable transform for instances that conform to a known structure.

Both Code System supplements and Concept Maps may be used to define relationships between concepts in different systems. ConceptMaps are assertions of the relationships between different concepts that are associated with particular contexts of use, while CodeSystem supplements are used to define inherent properties and semantics of the concepts in the code system

Background and Context

Further discussion of the issues involved in mapping between concept definition systems can be found in the HL7 v3 Core Principles document and the functionality described in the OMG CTS 2 specification.