Sets expectations for SDC-conformant systems around value set support for representing permitted question answers.

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.

An Extension

Optional Extension Element - found in all resources.

An Extension

Indicates an extension that must be supported by the system presenting the instance for data capture or end-user consumption. If a system does not recognize the extension or cannot implement the functionality defined by the extension, it should display an error message or warning and refrain from presenting the instance to the user or using it when capturing data.

This may point to extensions that control the appearance of data elements, control what value elements have, what elements are or are not available, what elements can or cannot be edited, or rules about how editing may occur. This extension does NOT apply when simply rendering a resource for publication purposes or for other purposes not intended for end-user data capture or data consumption.

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 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.

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.

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 element to indicate where the current master source of the resource can be found.

Allows the value set to be referenced by a single globally unique identifier.

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.

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 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.

Allows filtering of value sets that are appropriate for use versus not.See also the valueset-workflowStatus extension for additional status information related to the editorial process.

The lifecycle status of an artifact.

A Boolean value to indicate that this value set is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage.

Allows filtering of value sets that are appropriate for use versus not.

Enables experimental content to be developed following the same lifecycle that would be used for a production-level value set.

The date (and optionally time) when the value set was created or revised (e.g. the 'content logical definition').

Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the value set. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.

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.

This description can be used to capture details such as why the value set was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the value set as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the value set is presumed to be the predominant language in the place the value set was created).The description is not intended to describe the semantics of the Value Set - there are no intrinsic semantics separate from the codes contained in its expansion. The description should capture its intended use, which is needed for ensuring integrity for its use in models across future changes. A description 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 description.

If this is set to 'true', then no new versions of the content logical definition can be created. Note: Other metadata might still change.

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.

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).

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.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

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.

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.

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).

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).

Include one or more codes from a code system or other value set(s).

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'.

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.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

An absolute URI which is the code system from which the selected codes come from.

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.

The version of the code system that the codes are selected from, or the special version '*' for all versions.

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.

Specifies a concept to be included or excluded.

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.

An Extension

The label to list in front of a code when presenting a list of possible values in a questionnaire-like fashion.

​For questionnaires, see additional guidance and examples in the SDC implementation guide.

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

An Extension

Indicates an HTML style that should be applied when rendering this element.

This extension would be equivalent to setting the HTML "style" attribute on the root element for the element containing the extension.

NOTE: HTML styles can include references to external content (images, fonts, etc.), which may constitute a security issue, as resolving the link can allow tracking. See here for more detail.

​For questionnaires, see additional guidance and examples in the SDC implementation guide. This style applies to the base string. If there is also a rendering-xhtml or rendering-markdown extension, they must declare any relevant styles within those extension values.

Setting styles on elements can be risky. It presumes knowledge of how elements are rendered "by default". For example, setting the color of an element to 'blue' to highlight it might be fine - unless the default background color for a particular renderer is already blue. As well, it's not a given that all elements will be represented by a single HTML element. One element might be referenced by a collection of table cells that span rows and columns. Setting a border style on all of those cells wouldn't give the desired results and auto-tweaking the border style on each cell (deciding whether the border is top,left, right, etc.) would require complex coding. Finally, systems might not be using HTML for their UI at all and will need to map the specified styles to their own UI mechanism. For this reason, this element is best used when: a) the default UI characteristics are already well understood (because the specification applies to a single system or to a set of systems that are already required to comply with specific UI expectations b) the set of allowed style values is tightly controlled to only those that are necessary and sensible in that context

This is an equivalent of the string on which the extension is sent, but includes additional markdown (see documentation about markdown. Note that using HTML xhtml can allow for greater precision of display.

This is an equivalent of the string on which the extension is sent, but includes additional XHTML markup, such as bold, italics, styles, tables, etc. Existing restrictions on XHTML content apply. Note that using markdown allows for greater flexibility of display.

​For questionnaires, see additional guidance and examples in the SDC implementation guide.

Identifies the relative order in which concepts within the value set should be presented to a user.

The presence of a sort order implies that sort order is important.

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.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

Specifies a code for the concept to be included or excluded.

Expressions are allowed if defined by the underlying code system.

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.

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.

An Extension

Indicates an HTML style that should be applied when rendering this element.

This extension would be equivalent to setting the HTML "style" attribute on the root element for the element containing the extension.

NOTE: HTML styles can include references to external content (images, fonts, etc.), which may constitute a security issue, as resolving the link can allow tracking. See here for more detail.

​For questionnaires, see additional guidance and examples in the SDC implementation guide. This style applies to the base string. If there is also a rendering-xhtml or rendering-markdown extension, they must declare any relevant styles within those extension values.

Setting styles on elements can be risky. It presumes knowledge of how elements are rendered "by default". For example, setting the color of an element to 'blue' to highlight it might be fine - unless the default background color for a particular renderer is already blue. As well, it's not a given that all elements will be represented by a single HTML element. One element might be referenced by a collection of table cells that span rows and columns. Setting a border style on all of those cells wouldn't give the desired results and auto-tweaking the border style on each cell (deciding whether the border is top,left, right, etc.) would require complex coding. Finally, systems might not be using HTML for their UI at all and will need to map the specified styles to their own UI mechanism. For this reason, this element is best used when: a) the default UI characteristics are already well understood (because the specification applies to a single system or to a set of systems that are already required to comply with specific UI expectations b) the set of allowed style values is tightly controlled to only those that are necessary and sensible in that context

This is an equivalent of the string on which the extension is sent, but includes additional markdown (see documentation about markdown. Note that using HTML xhtml can allow for greater precision of display.

This is an equivalent of the string on which the extension is sent, but includes additional XHTML markup, such as bold, italics, styles, tables, etc. Existing restrictions on XHTML content apply. Note that using markdown allows for greater flexibility of display.

​For questionnaires, see additional guidance and examples in the SDC implementation guide.

Select concepts by specify 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, they SHALL all be true.

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.

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.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

A code that identifies a property or a filter defined in the code system.

The kind of operation to perform as a part of the filter criteria.

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.

The kind of operation to perform as a part of a property based filter.

The match value may be either a code defined by the system, or a string value, which is a regex match on the literal string of the property value (if the filter represents a property defined in CodeSystem) or of the system filter value (if the filter represents a filter defined in CodeSystem) when the operation is 'regex', or one of the values (true and false), when the operation is 'exists'.

Use regex matching with care - full regex matching on every SNOMED CT term is prohibitive, for example.

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 union of the contents of all of the referenced value sets.

The value set URI is either a logical reference to a defined value set such as a SNOMED CT reference set, 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.

Exclude one or more codes from the value set based on code system filters and/or other value sets.

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.

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.

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 resource.

An Extension

Optional Extension Element - found in all resources.

... Allows support for itemWeight and other key properties

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.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

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.

Typically, this uri is a UUID (e.g. urn:uuid:8230ff20-c97a-4167-a59d-dc2cb9df16dd).

The time at which the expansion was produced by the expanding system.

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.

The codes that are contained in the value set expansion.

An Extension

The label to list in front of a code when presenting a list of possible values in a questionnaire-like fashion.

​For questionnaires, see additional guidance and examples in the SDC implementation guide.

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

An Extension

Indicates an HTML style that should be applied when rendering this element.

This extension would be equivalent to setting the HTML "style" attribute on the root element for the element containing the extension.

NOTE: HTML styles can include references to external content (images, fonts, etc.), which may constitute a security issue, as resolving the link can allow tracking. See here for more detail.

​For questionnaires, see additional guidance and examples in the SDC implementation guide. This style applies to the base string. If there is also a rendering-xhtml or rendering-markdown extension, they must declare any relevant styles within those extension values.

Setting styles on elements can be risky. It presumes knowledge of how elements are rendered "by default". For example, setting the color of an element to 'blue' to highlight it might be fine - unless the default background color for a particular renderer is already blue. As well, it's not a given that all elements will be represented by a single HTML element. One element might be referenced by a collection of table cells that span rows and columns. Setting a border style on all of those cells wouldn't give the desired results and auto-tweaking the border style on each cell (deciding whether the border is top,left, right, etc.) would require complex coding. Finally, systems might not be using HTML for their UI at all and will need to map the specified styles to their own UI mechanism. For this reason, this element is best used when: a) the default UI characteristics are already well understood (because the specification applies to a single system or to a set of systems that are already required to comply with specific UI expectations b) the set of allowed style values is tightly controlled to only those that are necessary and sensible in that context

This is an equivalent of the string on which the extension is sent, but includes additional markdown (see documentation about markdown. Note that using HTML xhtml can allow for greater precision of display.

This is an equivalent of the string on which the extension is sent, but includes additional XHTML markup, such as bold, italics, styles, tables, etc. Existing restrictions on XHTML content apply. Note that using markdown allows for greater flexibility of display.

​For questionnaires, see additional guidance and examples in the SDC implementation guide.

Identifies the relative order in which concepts within the value set should be presented to a user.

The presence of a sort order implies that sort order is important.

Optional Extension Element - found in all resources.

... Allows support for itemWeight and other key properties

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.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

An absolute URI which is the code system in which the code for this item in the expansion is defined.

If true, this entry is included in the expansion for navigational purposes, and the user cannot select the code directly as a proper value.

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.

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.

The exact value of the version string is specified by the system from which the code is derived.

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.

The recommended display for this item in the expansion.

An Extension

Indicates an HTML style that should be applied when rendering this element.

This extension would be equivalent to setting the HTML "style" attribute on the root element for the element containing the extension.

NOTE: HTML styles can include references to external content (images, fonts, etc.), which may constitute a security issue, as resolving the link can allow tracking. See here for more detail.

​For questionnaires, see additional guidance and examples in the SDC implementation guide. This style applies to the base string. If there is also a rendering-xhtml or rendering-markdown extension, they must declare any relevant styles within those extension values.

Setting styles on elements can be risky. It presumes knowledge of how elements are rendered "by default". For example, setting the color of an element to 'blue' to highlight it might be fine - unless the default background color for a particular renderer is already blue. As well, it's not a given that all elements will be represented by a single HTML element. One element might be referenced by a collection of table cells that span rows and columns. Setting a border style on all of those cells wouldn't give the desired results and auto-tweaking the border style on each cell (deciding whether the border is top,left, right, etc.) would require complex coding. Finally, systems might not be using HTML for their UI at all and will need to map the specified styles to their own UI mechanism. For this reason, this element is best used when: a) the default UI characteristics are already well understood (because the specification applies to a single system or to a set of systems that are already required to comply with specific UI expectations b) the set of allowed style values is tightly controlled to only those that are necessary and sensible in that context

This is an equivalent of the string on which the extension is sent, but includes additional markdown (see documentation about markdown. Note that using HTML xhtml can allow for greater precision of display.

This is an equivalent of the string on which the extension is sent, but includes additional XHTML markup, such as bold, italics, styles, tables, etc. Existing restrictions on XHTML content apply. Note that using markdown allows for greater flexibility of display.

​For questionnaires, see additional guidance and examples in the SDC implementation guide.

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.

The designations provided must be based on the value set and code system definitions.

An Extension

Indicates an HTML style that should be applied when rendering this element.

This extension would be equivalent to setting the HTML "style" attribute on the root element for the element containing the extension.

NOTE: HTML styles can include references to external content (images, fonts, etc.), which may constitute a security issue, as resolving the link can allow tracking. See here for more detail.

​For questionnaires, see additional guidance and examples in the SDC implementation guide. This style applies to the base string. If there is also a rendering-xhtml or rendering-markdown extension, they must declare any relevant styles within those extension values.

Setting styles on elements can be risky. It presumes knowledge of how elements are rendered "by default". For example, setting the color of an element to 'blue' to highlight it might be fine - unless the default background color for a particular renderer is already blue. As well, it's not a given that all elements will be represented by a single HTML element. One element might be referenced by a collection of table cells that span rows and columns. Setting a border style on all of those cells wouldn't give the desired results and auto-tweaking the border style on each cell (deciding whether the border is top,left, right, etc.) would require complex coding. Finally, systems might not be using HTML for their UI at all and will need to map the specified styles to their own UI mechanism. For this reason, this element is best used when: a) the default UI characteristics are already well understood (because the specification applies to a single system or to a set of systems that are already required to comply with specific UI expectations b) the set of allowed style values is tightly controlled to only those that are necessary and sensible in that context

This is an equivalent of the string on which the extension is sent, but includes additional markdown (see documentation about markdown. Note that using HTML xhtml can allow for greater precision of display.

This is an equivalent of the string on which the extension is sent, but includes additional XHTML markup, such as bold, italics, styles, tables, etc. Existing restrictions on XHTML content apply. Note that using markdown allows for greater flexibility of display.

​For questionnaires, see additional guidance and examples in the SDC implementation guide.

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.

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

The text value for this designation.

Other codes and entries contained under this entry in the hierarchy.

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.

Sets expectations for SDC-conformant systems around value set support for representing permitted question answers.

The presence of a sort order implies that sort order is important.

... Allows support for itemWeight and other key properties

The presence of a sort order implies that sort order is important.

... Allows support for itemWeight and other key properties

Sets expectations for SDC-conformant systems around value set support for representing permitted question answers.

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.

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.

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.

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).

A human language.

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.

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.

An Extension

Optional Extension Element - found in all resources.

An Extension

Indicates an extension that must be supported by the system presenting the instance for data capture or end-user consumption. If a system does not recognize the extension or cannot implement the functionality defined by the extension, it should display an error message or warning and refrain from presenting the instance to the user or using it when capturing data.

This may point to extensions that control the appearance of data elements, control what value elements have, what elements are or are not available, what elements can or cannot be edited, or rules about how editing may occur. This extension does NOT apply when simply rendering a resource for publication purposes or for other purposes not intended for end-user data capture or data consumption.

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 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.

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.

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 element to indicate where the current master source of the resource can be found.

Allows the value set to be referenced by a single globally unique identifier.

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.

Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, and can then identify this value set outside of FHIR, where it is not possible to use the logical URI.

Allows externally provided and/or usable business identifiers to be easily associated with the module.

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.

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].

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.

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.

Support human navigation and code generation.

A short, descriptive, user-friendly title for the value set.

This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc.

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.

Allows filtering of value sets that are appropriate for use versus not.See also the valueset-workflowStatus extension for additional status information related to the editorial process.

The lifecycle status of an artifact.

A Boolean value to indicate that this value set is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage.

Allows filtering of value sets that are appropriate for use versus not.

Enables experimental content to be developed following the same lifecycle that would be used for a production-level value set.

The date (and optionally time) when the value set was created or revised (e.g. the 'content logical definition').

Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the value set. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.

The name of the organization or individual that published the value set.

Usually an organization but may be an individual. The publisher (or steward) of the value set is the organization or individual primarily responsible for the maintenance and upkeep of the value set. 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.

Helps establish the "authority/credibility" of the value set. May also allow for contact.

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.

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.

This description can be used to capture details such as why the value set was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the value set as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the value set is presumed to be the predominant language in the place the value set was created).The description is not intended to describe the semantics of the Value Set - there are no intrinsic semantics separate from the codes contained in its expansion. The description should capture its intended use, which is needed for ensuring integrity for its use in models across future changes. A description 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 description.

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.

When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.

Assist in searching for appropriate content.

A legal or geographic region in which the value set is intended to be used.

It may be possible for the value set to be used in jurisdictions other than those for which it was originally designed or intended.

Countries and regions within which this artifact is targeted for use.

If this is set to 'true', then no new versions of the content logical definition can be created. Note: Other metadata might still change.

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.

Explanation of why this value set is needed and why it has been designed as it has.

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.

A copyright statement relating to the value set and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the value set.

nullFrequently, the copyright differs between the value set and the codes that are included. The copyright statement should clearly differentiate between these when required.

Consumers must be able to determine any legal restrictions on the use of the value set and/or its content.

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).

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.