---
type: "resource-definitions"
title: "ValueSet Definitions"
resource: "ValueSet"
---
# ValueSet Definitions
## ValueSet
A set of codes drawn from one or more code systems
**Definition:** A ValueSet resource instance specifies a set of codes drawn from one or more code systems, intended for use in a particular context. Value sets link between [CodeSystem](codesystem.html) definitions and their use in [coded elements](terminologies.html).
**Cardinality:** 0..*
**Constraints:** cnl-0 | warning | Name should be usable as an identifier for the module by machine processing applications such as code generation | name.exists() implies name.matches('^[A-Z]([A-Za-z0-9_]){1,254}$')
**Mappings:** rim=N/A; w5=conformance.terminology
## ValueSet.url
Canonical identifier for this value set, represented as a URI (globally unique)
**Definition:** An absolute URI that is used to identify this value set when it is referenced in a specification, model, design or an instance; also called its canonical identifier. This SHOULD be globally unique and SHOULD be a literal address at which an authoritative instance of this value set is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the value set is stored on different servers.
**Comments:** Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred. Multiple instances may share the same URL if they have a distinct version.
The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author. Considerations for making this decision are found in [Technical and Business Versions](resource.html#versions).
In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the [meta.source](resource.html#meta) element to indicate where the current master source of the resource can be found.
**Requirements:** Allows the value set to be referenced by a single globally unique identifier.
**Cardinality:** 0..1
**Type:** [uri](/uri)
**Summary:** true
**Constraints:** cnl-1 | warning | URL should not contain | or # - these characters make processing canonical references problematic | exists() implies matches('^[^|# ]+$')
**Mappings:** w5=FiveWs.identifier; rim=N/A
## ValueSet.identifier
Additional identifier for the value set (business identifier)
**Definition:** A formal identifier that is used to identify this value set when it is represented in other formats, or referenced in a specification, model, design or an instance.
**Requirements:** Allows externally provided and/or usable business identifiers to be easily associated with the module.
**Cardinality:** 0..*
**Type:** [Identifier](/Identifier)
**Summary:** true
**Mappings:** w5=FiveWs.identifier; objimpl=no-gen-base
## ValueSet.version
Business version of the value set
**Definition:** The identifier that is used to identify this version of the value set when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the value set 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.
**Comments:** There may be different value set 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 value set with the format [url]|[version]. The version SHOULD NOT contain a '#' - see [Business Version](resource.html#bv-format).
**Cardinality:** 0..1
**Type:** [string](/string)
**Summary:** true
**Mappings:** w5=FiveWs.version
## ValueSet.versionAlgorithm[x]
How to compare versions
**Definition:** Indicates the mechanism used to compare versions to determine which ValueSet is more current.
**Comments:** If set as a string, this is a FHIRPath expression that has two additional context variables passed in - %version1 and %version2 and will return a negative number if version1 is newer, a positive number if version2 and a 0 if the version ordering can't be successfully be determined.
**Cardinality:** 0..1
**Type:** [string](/string), [Coding](/Coding)
**Binding:** extensible:[version-algorithm](/valueset-version-algorithm)
**Summary:** true
## ValueSet.name
Name for this value set (computer friendly)
**Definition:** A natural language name identifying the value set. This name should be usable as an identifier for the module by machine processing applications such as code generation.
**Comments:** 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.A name should be provided unless the value set is a contained resource (e.g. an anonymous value set in a profile). Most registries will require a name.
**Requirements:** Support human navigation and code generation.
**Conditions:** cnl-0
**Cardinality:** 0..1
**Type:** [string](/string)
**Summary:** true
## ValueSet.title
Name for this value set (human friendly)
**Definition:** A short, descriptive, user-friendly title for the value set.
**Comments:** This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc.
**Cardinality:** 0..1
**Type:** [string](/string)
**Summary:** true
## ValueSet.status
draft | active | retired | unknown
**Definition:** The status of this value set. Enables tracking the life-cycle of the content. The status of the value set applies to the value set definition (ValueSet.compose) and the associated ValueSet metadata. Expansions do not have a state.
**Comments:** Allows filtering of value sets that are appropriate for use versus not.See also the [[[http://hl7.org/fhir/StructureDefinition/valueset-workflowStatusDescription]]] extension for additional status information related to the editorial process.
See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).
**Cardinality:** 1..1
**Type:** [code](/code)
**Binding:** required:[publication-status](/valueset-publication-status)
**Summary:** true
**Is Modifier:** true (Reason: This is labeled as "Is Modifier" because applications should not use a retired {{title}} without due consideration)
**Mappings:** w5=FiveWs.status
## ValueSet.experimental
For testing only - never for real usage
**Definition:** A Boolean value to indicate that this value set is authored for testing purposes (or education/evaluation/marketing) and no version of this resource will ever be intended for genuine usage.
**Comments:** Allows filtering of value sets that are appropriate for use versus not.. Experimental resources might include example instances in implementation guides, instances created solely for testing purposes, etc
**Requirements:** Enables experimental content to be developed following the same lifecycle that would be used for a production-level value set.
**Meaning if Missing:** If absent, this resource is treated as though it is not experimental.
**Cardinality:** 0..1
**Type:** [boolean](/boolean)
**Summary:** true
**Mappings:** w5=FiveWs.class
## ValueSet.date
Date last changed
**Definition:** The date (and optionally time) when the value set metadata or content logical definition (.compose) was created or revised.
**Comments:** Note that this is not the same as the meta.lastUpdated which is specific to an instance of a value set resource on a server. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.
See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).
**Aliases:** Revision Date
**Cardinality:** 0..1
**Type:** [dateTime](/dateTime)
**Summary:** true
**Mappings:** w5=FiveWs.recorded; rim=N/A
## ValueSet.publisher
Name of the publisher/steward (organization or individual)
**Definition:** The name of the organization or individual responsible for the release and ongoing maintenance of the value set.
**Comments:** Usually an organization but may be an individual. 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 value set. This item SHOULD be populated unless the information is available from context.
**Requirements:** Helps establish the "authority/credibility" of the value set. May also allow for contact.
**Cardinality:** 0..1
**Type:** [string](/string)
**Summary:** true
**Mappings:** w5=FiveWs.witness
## ValueSet.contact
Contact details for the publisher
**Definition:** Contact details to assist a user in finding and communicating with the publisher.
**Comments:** May be a web site, an email address, a telephone number, etc.
See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).
**Cardinality:** 0..*
**Type:** [ContactDetail](/ContactDetail)
**Summary:** true
## ValueSet.description
Natural language description of the value set
**Definition:** A free text natural language description of the value set from a consumer's perspective. The textual description specifies the span of meanings for concepts to be included within the Value Set Expansion, and also may specify the intended use and limitations of the Value Set.
**Comments:** Description SHOULD contain instructions for clinical or administrative use and interpretation and information about misuse. Description SHOULD be populated unless the information is available from context. Description SHOULD be populated unless the value set is a contained resource (e.g. a value set defined solely in the context of a profile).
**Cardinality:** 0..1
**Type:** [markdown](/markdown)
**Mappings:** rim=N/A
## ValueSet.useContext
The context that the content is intended to support
**Definition:** 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 value set instances.
**Comments:** When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.
**Requirements:** Assist in searching for appropriate content.
**Cardinality:** 0..*
**Type:** [UsageContext](/UsageContext)
**Summary:** true
## ValueSet.jurisdiction
Jurisdiction of the authority that maintains the value set (if applicable)
**Definition:** A legal or geographic region in which the authority that maintains the resource is operating. In general, the jurisdiction is also found in the useContext. The useContext may reference additional jurisdictions because the defining jurisdiction does not necessarily limit the jurisdictions of use.
**Comments:** It may be possible for the value set to be used in jurisdictions other than those for which it was originally designed or intended.
DEPRECATION NOTE: For consistency, implementations are encouraged to migrate to using the new 'jurisdiction' code in the useContext element. (I.e. useContext.code indicating http://terminology.hl7.org/CodeSystem/usage-context-type#jurisdiction and useContext.valueCodeableConcept indicating the jurisdiction.)
**Cardinality:** 0..*
**Type:** [CodeableConcept](/CodeableConcept)
**Binding:** extensible:[jurisdiction](/valueset-jurisdiction)
**Summary:** true
## ValueSet.immutable
Indicates whether or not any change to the content logical definition may occur
**Definition:** If this is set to 'true', then no new versions of the content logical definition can be created. Note: Other metadata might still change.
**Comments:** Normally immutability is set to 'false', which is the default assumption if it is not populated. Note that the implication is that if this is set to 'true', there may be only one ValueSet version for this definition. Immutability tends to be set to 'true' in one of two cases: - Where the value set, by the nature of its usage, cannot change. For example "All specializations of ACT in ActClassCode" - Where there's no safe way to express the "Purpose" such that someone else could safely make changes to the value set definition. Source workflow control must guarantee that the same URI always yields the same definition.
**Cardinality:** 0..1
**Type:** [boolean](/boolean)
**Summary:** true
## ValueSet.purpose
Why this value set is defined
**Definition:** Explanation of why this value set is needed and why it has been designed as it has.
**Comments:** This element does not describe the usage of the value set. 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 value set.
**Cardinality:** 0..1
**Type:** [markdown](/markdown)
**Mappings:** w5=FiveWs.why[x]; objimpl=no-gen-base
## ValueSet.copyright
Notice about intellectual property ownership, can include restrictions on use
**Definition:** A copyright statement relating to the value set and/or its contents. Copyright statements are notices of intellectual property ownership and can include restrictions on the use and publishing of the value set.
**Comments:** Frequently, the copyright differs between the value set and the codes that are included. The copyright statement should clearly differentiate between these when required.
**Requirements:** Consumers must be able to determine any legal restrictions on the use of the value set and/or its content.
**Aliases:** License, Restrictions
**Cardinality:** 0..1
**Type:** [markdown](/markdown)
**Mappings:** objimpl=no-gen-base
## ValueSet.copyrightLabel
Copyright holder and year(s)
**Definition:** A short string (<50 characters), suitable for inclusion in a page footer that identifies the copyright holder, effective period, and optionally whether rights are restricted. (e.g. 'All rights reserved', 'Some rights reserved').
**Comments:** The copyright symbol and the '(c)' textual representation SHOULD NOT be included in this string. It will be added by software when rendering the notation. Full details about licensing, restrictions, warrantees, etc. goes in the more general 'copyright' element.
**Requirements:** Defines the content expected to be rendered in all representations of the artifact.
**Cardinality:** 0..1
**Type:** [string](/string)
## ValueSet.approvalDate
When the ValueSet was approved by publisher
**Definition:** The date on which the resource content was approved by the publisher. Approval happens once when the content is officially approved for usage.
**Comments:** The 'date' element may be more recent than the approval date because of minor changes or editorial corrections.
See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).
**Cardinality:** 0..1
**Type:** [date](/date)
**Mappings:** objimpl=no-gen-base
## ValueSet.lastReviewDate
When the ValueSet was last reviewed by the publisher
**Definition:** The date on which the resource content was last reviewed. Review happens periodically after approval but does not change the original approval date.
**Comments:** If specified, this date follows the original approval date.
See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).
**Requirements:** Gives a sense of how "current" the content is. Resources that have not been reviewed in a long time may have a risk of being less appropriate/relevant.
**Cardinality:** 0..1
**Type:** [date](/date)
**Mappings:** objimpl=no-gen-base
## ValueSet.effectivePeriod
When the ValueSet is expected to be used
**Definition:** The period during which the ValueSet content was or is planned to be in active use.
**Comments:** The effective period for a ValueSet determines when the content is applicable for usage and is independent of publication and review dates. For example, a valueset intended to be used for the year 2016 might be published in 2015.
See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).
**Requirements:** Allows establishing a transition before a resource comes into effect and also allows for a sunsetting process when new versions of the ValueSet are or are expected to be used instead.
**Cardinality:** 0..1
**Type:** [Period](/Period)
**Summary:** true
**Mappings:** objimpl=no-gen-base
## ValueSet.topic
E.g. Education, Treatment, Assessment, etc
**Definition:** Descriptions related to the content of the ValueSet. Topics provide a high-level categorization as well as keywords for the ValueSet that can be useful for filtering and searching.
**Comments:** DEPRECATION NOTE: For consistency, implementations are encouraged to migrate to using the new 'topic' code in the useContext element. (I.e. useContext.code indicating http://terminology.hl7.org/CodeSystem/usage-context-type#topic and useContext.valueCodeableConcept indicating the topic)
**Requirements:** Repositories must be able to determine how to categorize the ValueSet so that it can be found by topical and keyword searches.
**Cardinality:** 0..*
**Type:** [CodeableConcept](/CodeableConcept)
**Binding:** example:[definition-topic](/valueset-definition-topic)
## ValueSet.author
Who authored the ValueSet
**Definition:** An individiual or organization primarily involved in the creation and maintenance of the ValueSet.
**Cardinality:** 0..*
**Type:** [ContactDetail](/ContactDetail)
## ValueSet.editor
Who edited the ValueSet
**Definition:** An individual or organization primarily responsible for internal coherence of the ValueSet.
**Cardinality:** 0..*
**Type:** [ContactDetail](/ContactDetail)
## ValueSet.reviewer
Who reviewed the ValueSet
**Definition:** An individual or organization asserted by the publisher to be primarily responsible for review of some aspect of the ValueSet.
**Comments:** See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).
**Cardinality:** 0..*
**Type:** [ContactDetail](/ContactDetail)
## ValueSet.endorser
Who endorsed the ValueSet
**Definition:** An individual or organization asserted by the publisher to be responsible for officially endorsing the ValueSet for use in some setting.
**Comments:** See guidance around (not) making local changes to elements [here](canonicalresource.html#localization).
**Cardinality:** 0..*
**Type:** [ContactDetail](/ContactDetail)
## ValueSet.relatedArtifact
Additional documentation, citations, etc
**Definition:** Related artifacts such as additional documentation, justification, dependencies, bibliographic references, and predecessor and successor artifacts.
**Comments:** Each related artifact is either an attachment, or a reference to another resource, but not both.
**Requirements:** A ValueSet must be able to provide enough information for consumers of the content (and/or interventions or results produced by the content) to be able to determine and understand the justification for and evidence in support of the content. If the type is `successor` or `predecessor`, the related resource must be a ValueSet.
**Cardinality:** 0..*
**Type:** [RelatedArtifact](/RelatedArtifact)
**Constraints:** vsd-12 | error | Related artifact can't be depends-on or composed-of | (type in ('depends-on' | 'composed-of')).not()
## ValueSet.compose
Content logical definition of the value set (CLD)
**Definition:** A set of criteria that define the contents of the value set by including or excluding codes selected from the specified code system(s) that the value set draws from. This is also known as the Content Logical Definition (CLD).
**Aliases:** Content Logical Definition, CLD
**Cardinality:** 0..1
**Type:** [BackboneElement](/BackboneElement)
## ValueSet.compose.lockedDate
Fixed date for references with no specified version (transitive)
**Definition:** The Locked Date is the effective date that is used to determine the version of all referenced Code Systems and Value Set Definitions included in the compose that are not already tied to a specific version.
**Comments:** With a defined lockedDate the value set is considered "Locked". Otherwise, the value set may have different expansions as underlying code systems and/or value sets evolve. The interpretation of lockedDate is often dependent on the context - e.g. a SNOMED CT derived value set with a lockedDate will have a different expansion in USA than in UK. If a value set specifies a version for include and exclude statements, and also specifies a locked date, the specified versions need to be available that date, or the value set will not be usable.
**Cardinality:** 0..1
**Type:** [date](/date)
**Summary:** true
**Mappings:** w5=FiveWs.init
## ValueSet.compose.inactive
Whether inactive codes are in the value set
**Definition:** Whether inactive codes - codes that are not approved for current use - are in the value set. If inactive = true, inactive codes are to be included in the expansion, if inactive = false, the inactive codes will not be included in the expansion. If absent, the behavior is determined by the implementation, or by the applicable $expand parameters (but generally, inactive codes would be expected to be included).
**Comments:** Note that in the FHIR terminology framework, "deprecated" does not mean inactive, but in some code systems, e.g. LOINC, "deprecated" does mean inactive. Code systems should define what codes are considered to be inactive. If this is not clearly defined (including in the FHIR code system resource), then all codes are assumed to be active.
The Value Set Definition specification defines an ActiveOnly element, which is the reverse of this element e.g. (ValueSet.compose.inactive=FALSE) is the same as (VSD.ActiveOnly=TRUE).
**Cardinality:** 0..1
**Type:** [boolean](/boolean)
**Summary:** true
## ValueSet.compose.include
Include one or more codes from a code system or other value set(s)
**Definition:** Include one or more codes from a code system or other value set(s).
**Comments:** All the conditions in an include must be true. If a system is listed, all the codes from the system are listed. If one or more filters are listed, all of the filters must apply. If one or more value sets are listed, the codes must be in all the value sets. E.g. each include is 'include all the codes that meet all these conditions'.
**Cardinality:** 1..*
**Type:** [BackboneElement](/BackboneElement)
**Summary:** true
**Constraints:** vsd-2 | error | A value set with concepts or filters SHALL include a system | (concept.exists() or filter.exists()) implies system.exists(); vsd-3 | error | Cannot have both concept and filter | concept.empty() or filter.empty(); vsd-1 | error | A value set include/exclude SHALL have a value set or a system | valueSet.exists() or system.exists()
**Mappings:** rim=N/A
## ValueSet.compose.include.system
The system the codes come from
**Definition:** An absolute URI which is the code system from which the selected codes come from.
**Comments:** If there are no codes or filters, the entire code system is included. Note that the set of codes that are included may contain abstract codes. See ''Coding.system'' for further documentation about the correct value for the system element. If a contained code system is referenced, the entire canonical url must be provided.
**Conditions:** vsd-2, vsd-1
**Cardinality:** 0..1
**Type:** [uri](/uri)
**Summary:** true
**Mappings:** rim=N/A
## ValueSet.compose.include.version
Specific version of the code system referred to
**Definition:** The version of the code system that the codes are selected from, or the special version '*' for all versions.
**Comments:** This is used when selecting the descendants of a concept - they may change between versions. If no version is specified, then the exact contents of the value set might not be known until a context of use binds it to a particular version. The special value '*' means all versions; It is at server discretion regarding expansions and which versions must be supported.
**Cardinality:** 0..1
**Type:** [string](/string)
**Summary:** true
**Mappings:** rim=N/A
## ValueSet.compose.include.concept
A concept defined in the system
**Definition:** Specifies a concept to be included or excluded.
**Comments:** The list of concepts is considered ordered, though the order might not have any particular significance. Typically, the order of an expansion follows that defined in the compose element.
**Conditions:** vsd-2, vsd-3
**Cardinality:** 0..*
**Type:** [BackboneElement](/BackboneElement)
**Mappings:** rim=N/A
## ValueSet.compose.include.concept.code
Code or expression from system
**Definition:** Specifies a code for the concept to be included or excluded.
**Comments:** Expressions are allowed if defined by the underlying code system.
**Cardinality:** 1..1
**Type:** [code](/code)
**Mappings:** rim=N/A
## ValueSet.compose.include.concept.display
Text to display for this code for this value set in this valueset
**Definition:** The text to display to the user for this concept in the context of this valueset. If no display is provided, then applications using the value set use the display specified for the code by the system.
**Comments:** The value set resource allows for an alternative display to be specified for when this concept is used in this particular value set. See notes in the value set narrative about the correct use of this element.
**Cardinality:** 0..1
**Type:** [string](/string)
**Mappings:** rim=N/A
## ValueSet.compose.include.concept.designation
Additional representations for this concept
**Definition:** Additional representations for this concept when used in this value set - other languages, aliases, specialized purposes, used for particular purposes, etc.
**Comments:** Concepts have both a ```display``` and an array of ```designation```. The display is equivalent to a special designation with an implied ```designation.use``` of "primary code" and a language equal to the [Resource Language](resource.html#language).
**Cardinality:** 0..*
**Type:** [BackboneElement](/BackboneElement)
**Constraints:** vsd-11 | error | Must have a value for concept.designation.use if concept.designation.additionalUse is present | additionalUse.exists() implies use.exists()
## ValueSet.compose.include.concept.designation.language
Human language of the designation
**Definition:** The language this designation is defined for.
**Comments:** In the absence of a language, the resource language applies.
**Cardinality:** 0..1
**Type:** [code](/code)
**Binding:** required:[all-languages](/valueset-all-languages)
## ValueSet.compose.include.concept.designation.use
Types of uses of designations
**Definition:** A code that represents types of uses of designations.
**Comments:** If no use is provided, the designation can be assumed to be suitable for general display to a human user.
**Conditions:** vsd-11
**Cardinality:** 0..1
**Type:** [Coding](/Coding)
**Binding:** extensible:[designation-use](/valueset-designation-use)
## ValueSet.compose.include.concept.designation.additionalUse
Additional ways how this designation would be used
**Definition:** Additional codes that detail how this designation would be used, if there is more than one use.
**Comments:** This was added rather than increasing the cardinality of .use to 0..* in order to maintain backward compatibility.
**Conditions:** vsd-11
**Cardinality:** 0..*
**Type:** [Coding](/Coding)
**Binding:** extensible:[designation-use](/valueset-designation-use)
## ValueSet.compose.include.concept.designation.value
The text value for this designation
**Definition:** The text value for this designation.
**Cardinality:** 1..1
**Type:** [string](/string)
## ValueSet.compose.include.filter
Select codes/concepts by their properties (including relationships)
**Definition:** Select concepts by specifying a matching criterion based on the properties (including relationships) defined by the system, or on filters defined by the system. If multiple filters are specified within the include, they SHALL all be true.
**Comments:** Selecting codes by specifying filters based on properties is only possible where the underlying code system defines appropriate properties. Note that in some cases, the underlying code system defines the logical concepts but not the literal codes for the concepts. In such cases, the literal definitions may be provided by a third party.
**Conditions:** vsd-2, vsd-3
**Cardinality:** 0..*
**Type:** [BackboneElement](/BackboneElement)
**Summary:** true
**Mappings:** rim=N/A
## ValueSet.compose.include.filter.property
A property/filter defined by the code system
**Definition:** A code that identifies a property or a filter defined in the code system.
**Cardinality:** 1..1
**Type:** [code](/code)
**Summary:** true
**Mappings:** rim=N/A
## ValueSet.compose.include.filter.op
= | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | child-of | descendent-leaf | exists
**Definition:** The kind of operation to perform as a part of the filter criteria.
**Comments:** In case filter.property represents a property of the system, the operation applies to the selected property. In case filter.property represents a filter of the system, the operation SHALL match one of the CodeSystem.filter.operator values.
**Cardinality:** 1..1
**Type:** [code](/code)
**Binding:** required:[filter-operator](/valueset-filter-operator)
**Summary:** true
**Mappings:** rim=N/A
## ValueSet.compose.include.filter.value
Code from the system, or regex criteria, or boolean value for exists
**Definition:** ValueSet.compose.include.filter.value is represented as a string, and the string value must be [as described](valueset.html#filter-values).
**Comments:** Use regex matching with care - full regex matching on every SNOMED CT term is prohibitive, for example.
**Cardinality:** 1..1
**Type:** [string](/string)
**Summary:** true
**Mappings:** rim=N/A
## ValueSet.compose.include.valueSet
Select the contents included in this value set
**Definition:** Selects the concepts found in this value set (based on its value set definition). This is an absolute URI that is a reference to ValueSet.url. If multiple value sets are specified this includes the intersection of the contents of all of the referenced value sets.
**Comments:** The value set URI is either a logical reference to a defined value set such as a [SNOMED CT reference set](https://terminology.hl7.org/SNOMEDCT.html), or a direct reference to a value set definition using ValueSet.url. The reference might not refer to an actual FHIR ValueSet resource; in this case, whatever is referred to is an implicit definition of a value set that needs to be clear about how versions are resolved.
**Conditions:** vsd-1
**Cardinality:** 0..*
**Type:** [canonical](/canonical)
**Summary:** true
**Mappings:** rim=N/A
## ValueSet.compose.include.copyright
A copyright statement for the specific code system included in the value set
**Definition:** A copyright statement for the specific code system asserted by the containing ValueSet.compose.include element's system value (if the associated ValueSet.compose.include.version element is not present); or the code system and version combination (if the associated ValueSet.compose.include.version element is present).
**Cardinality:** 0..1
**Type:** [markdown](/markdown)
**Mappings:** rim=N/A
## ValueSet.compose.exclude
Explicitly exclude codes from a code system or other value sets
**Definition:** Exclude one or more codes from the value set based on code system filters and/or other value sets.
**Comments:** Usually this is used to selectively exclude codes that were included by subsumption in the inclusions. Any display names specified for the codes are ignored.
**Cardinality:** 0..*
**Mappings:** rim=N/A
## ValueSet.compose.property
Property to return if client doesn't override
**Definition:** A property to return in the expansion, if the client doesn't ask for any particular properties. May be either a code from the code system definition (convenient) or a the formal URI that refers to the property. The special value '*' means all properties known to the server.
**Comments:** Note that property names can clash, so using a URI is recommended.
**Cardinality:** 0..*
**Type:** [string](/string)
## ValueSet.expansion
Used when the value set is "expanded"
**Definition:** A value set can also be "expanded", where the value set is turned into a simple collection of enumerated codes. This element holds the expansion, if it has been performed.
**Comments:** Expansion is performed to produce a collection of codes that are ready to use for data entry or validation. Value set expansions are always considered to be stateless - they are a record of the set of codes in the value set at a point in time under a given set of conditions, and are not subject to ongoing maintenance.
Expansion.parameter is a simplified list of parameters - a subset of the features of the [Parameters](parameters.html) resource.
**Cardinality:** 0..1
**Type:** [BackboneElement](/BackboneElement)
## ValueSet.expansion.identifier
Identifies the value set expansion (business identifier)
**Definition:** An identifier that uniquely identifies this expansion of the valueset, based on a unique combination of the provided parameters, the system default parameters, and the underlying system code system versions etc. Systems may re-use the same identifier as long as those factors remain the same, and the expansion is the same, but are not required to do so. This is a business identifier.
**Comments:** Typically, this uri is a UUID (e.g. urn:uuid:8230ff20-c97a-4167-a59d-dc2cb9df16dd).
**Cardinality:** 0..1
**Type:** [uri](/uri)
## ValueSet.expansion.next
Opaque urls for paging through expansion results
**Definition:** As per paging Search results, the next URLs are opaque to the client, have no dictated structure, and only the server understands them.
**Comments:** Clients SHOULD use the next link, if present, to page through expansion results in preference to using the offset and count parameters. Due to the optional nature of the next link, its absence does not necessarily indicate that it is the last page of results. Instead, as the offset and count parameters SHALL be populated when paging, clients can reliably use the count/offset parameters to determine whether the whole expansion is returned.
**Cardinality:** 0..1
**Type:** [uri](/uri)
## ValueSet.expansion.timestamp
Time ValueSet expansion happened
**Definition:** The time at which the expansion was produced by the expanding system.
**Comments:** This SHOULD be a fully populated instant, but in some circumstances, value sets are expanded by hand, and the expansion is published without that precision.
**Cardinality:** 1..1
**Type:** [dateTime](/dateTime)
## ValueSet.expansion.total
Total number of codes in the expansion
**Definition:** The total number of concepts in the expansion. If the number of concept nodes in this resource is less than the stated number, then the server can return more using the offset parameter.
**Comments:** Paging only applies to flat expansions.
**Cardinality:** 0..1
**Type:** [integer](/integer)
## ValueSet.expansion.offset
Offset at which this resource starts
**Definition:** If paging is being used, the offset at which this resource starts. I.e. this resource is a partial view into the expansion. If paging is not being used, this element SHALL NOT be present.
**Comments:** Paging only applies to flat expansions. If a filter is applied, the count is the number of concepts that matched the filter, not the number of concepts in an unfiltered view of the expansion.
**Meaning if Missing:** Paging is not being used
**Cardinality:** 0..1
**Type:** [integer](/integer)
## ValueSet.expansion.parameter
Parameter that controlled the expansion process
**Definition:** A parameter that controlled the expansion process. These parameters may be used by users of expanded value sets to check whether the expansion is suitable for a particular purpose, or to pick the correct expansion.
**Comments:** The server decides which parameters to include here, but at a minimum, the list SHOULD include all of the parameters that affect the $expand operation. If the expansion will be persisted all of these parameters SHALL be included. If the codeSystem on the server has a specified version then this version SHALL be provided as a parameter in the expansion (note that not all code systems have a version).
**Cardinality:** 0..*
**Type:** [BackboneElement](/BackboneElement)
## ValueSet.expansion.parameter.name
Name as assigned by the client or server
**Definition:** Name of the input parameter to the $expand operation; may be a server-assigned name for additional default or other server-supplied parameters used to control the expansion process.
**Comments:** The names are assigned at the discretion of the server.
**Cardinality:** 1..1
**Type:** [string](/string)
## ValueSet.expansion.parameter.value[x]
Value of the named parameter
**Definition:** The value of the parameter.
**Cardinality:** 0..1
**Type:** [string](/string), [boolean](/boolean), [integer](/integer), [decimal](/decimal), [uri](/uri), [code](/code), [dateTime](/dateTime)
## ValueSet.expansion.property
Additional information supplied about each concept
**Definition:** A property defines an additional slot through which additional information can be provided about a concept.
**Cardinality:** 0..*
**Type:** [BackboneElement](/BackboneElement)
## ValueSet.expansion.property.code
Identifies the property on the concepts, and when referred to in operations
**Definition:** A code that is used to identify the property. The code is used in ValueSet.expansion.contains.property.code.
**Cardinality:** 1..1
**Type:** [code](/code)
## ValueSet.expansion.property.uri
Formal identifier for the property
**Definition:** Reference to the formal meaning of the property. One possible source of meaning is the [Concept Properties](codesystem-concept-properties.html) code system.
**Cardinality:** 0..1
**Type:** [uri](/uri)
## ValueSet.expansion.contains
Codes in the value set
**Definition:** The codes that are contained in the value set expansion.
**Cardinality:** 0..*
**Type:** [BackboneElement](/BackboneElement)
**Constraints:** vsd-6 | error | SHALL have a code or a display | code.exists() or display.exists(); vsd-9 | error | SHALL have a code if not abstract | code.exists() or abstract = true; vsd-10 | error | SHALL have a system if a code is present | code.empty() or system.exists()
## ValueSet.expansion.contains.system
System value for the code
**Definition:** An absolute URI which is the code system in which the code for this item in the expansion is defined.
**Conditions:** vsd-10
**Cardinality:** 0..1
**Type:** [uri](/uri)
## ValueSet.expansion.contains.abstract
If user cannot select this entry
**Definition:** If true, this entry is included in the expansion for navigational purposes, and the user cannot select the code directly as a proper value.
**Comments:** This should not be understood to exclude its use for searching (e.g. by subsumption testing). The client should know whether it is appropriate for the user to select an abstract code or not.
**Meaning if Missing:** If this is not populated, systems can assume that the concept it not abstract. This SHALL always be populated for abstract concepts
**Conditions:** vsd-9
**Cardinality:** 0..1
**Type:** [boolean](/boolean)
## ValueSet.expansion.contains.inactive
If concept is inactive in the code system
**Definition:** If the concept is inactive in the code system that defines it. Inactive codes are those that are no longer to be used, but are maintained by the code system for understanding legacy data. It might not be known or specified whether a concept is inactive (and it may depend on the context of use).
**Comments:** This should only have a value if the concept is inactive.
**Cardinality:** 0..1
**Type:** [boolean](/boolean)
## ValueSet.expansion.contains.version
Version in which this code/display is defined
**Definition:** The version of the code system from this code was taken. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
**Comments:** The exact value of the version string is specified by the system from which the code is derived.
**Cardinality:** 0..1
**Type:** [string](/string)
## ValueSet.expansion.contains.code
Code - if blank, this is not a selectable code
**Definition:** The code for this item in the expansion hierarchy. If this code is missing the entry in the hierarchy is a place holder (abstract) and does not represent a valid code in the value set.
**Conditions:** vsd-6, vsd-9, vsd-10
**Cardinality:** 0..1
**Type:** [code](/code)
## ValueSet.expansion.contains.display
User display for the concept
**Definition:** The recommended display for this item in the expansion.
**Conditions:** vsd-6
**Cardinality:** 0..1
**Type:** [string](/string)
## ValueSet.expansion.contains.designation
Additional representations for this item
**Definition:** Additional representations for this item - other languages, aliases, specialized purposes, used for particular purposes, etc. These are relevant when the conditions of the expansion do not fix to a single correct representation.
**Comments:** The designations provided must be based on the value set and code system definitions.
**Cardinality:** 0..*
## ValueSet.expansion.contains.property
Property value for the concept
**Definition:** A property value for this concept.
**Cardinality:** 0..*
**Type:** [BackboneElement](/BackboneElement)
## ValueSet.expansion.contains.property.code
Reference to ValueSet.expansion.property.code
**Definition:** A code that is a reference to ValueSet.expansion.property.code.
**Cardinality:** 1..1
**Type:** [code](/code)
## ValueSet.expansion.contains.property.value[x]
Value of the property for this concept
**Definition:** The value of this property.
**Cardinality:** 1..1
**Type:** [code](/code), [Coding](/Coding), [string](/string), [integer](/integer), [boolean](/boolean), [dateTime](/dateTime), [decimal](/decimal)
## ValueSet.expansion.contains.property.subProperty
SubProperty value for the concept
**Definition:** A subproperty value for this concept.
**Cardinality:** 0..*
**Type:** [BackboneElement](/BackboneElement)
## ValueSet.expansion.contains.property.subProperty.code
Reference to ValueSet.expansion.property.code
**Definition:** A code that is a reference to ValueSet.expansion.property.code.
**Cardinality:** 1..1
**Type:** [code](/code)
## ValueSet.expansion.contains.property.subProperty.value[x]
Value of the subproperty for this concept
**Definition:** The value of this subproperty.
**Cardinality:** 1..1
**Type:** [code](/code), [Coding](/Coding), [string](/string), [integer](/integer), [boolean](/boolean), [dateTime](/dateTime), [decimal](/decimal)
## ValueSet.expansion.contains.contains
Codes contained under this entry
**Definition:** Other codes and entries contained under this entry in the hierarchy.
**Comments:** If the expansion uses this element, there is no implication about the logical relationship between them, and the structure cannot be used for logical inferencing. The structure exists to provide navigational assistance for helping human users to locate codes in the expansion.
**Cardinality:** 0..*